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Four Segments"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Four Segments</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Several months later Alex finally got his brother Bob's creation by post. And now, in his turn, Alex wants to boast about something to his brother. He thought for a while, and came to the conclusion that he has no ready creations, and decided to write a program for rectangles detection. According to his plan, the program detects if the four given segments form a rectangle of a positive area and with sides parallel to coordinate axes. As Alex does badly at school and can't write this program by himself, he asks you to help him.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input data contain four lines. Each of these lines contains four integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span> (<span class=\"tex-span\">โ-โ10<sup class=\"upper-index\">9</sup>โโคโ<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>,โ<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>โโคโ10<sup class=\"upper-index\">9</sup></span>) โ coordinates of segment's beginning and end positions. The given segments can degenerate into points.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the word ยซ<span class=\"tex-font-style-tt\">YES</span>ยป, if the given four segments form the required rectangle, otherwise output ยซ<span class=\"tex-font-style-tt\">NO</span>ยป.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 6 1<br/>1 0 6 0<br/>6 0 6 1<br/>1 1 1 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>0 0 0 3<br/>2 0 0 0<br/>2 2 2 0<br/>0 2 2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"e98f4356edb511df379e39a2f064c413\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"9cbc35cd4f0589a8d7b11e3fe4015811ce6ba465\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_e54041463d8098a734001fcfacdc636e317e364e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Four Segments</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Several months later Alex finally got his brother Bob's creation by post. And now, in his turn, Alex wants to boast about something to his brother. He thought for a while, and came to the conclusion that he has no ready creations, and decided to write a program for rectangles detection. According to his plan, the program detects if the four given segments form a rectangle of a positive area and with sides parallel to coordinate axes. As Alex does badly at school and can't write this program by himself, he asks you to help him.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input data contain four lines. Each of these lines contains four integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span> (<span class=\"tex-span\">โ-โ10<sup class=\"upper-index\">9</sup>โโคโ<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>,โ<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>โโคโ10<sup class=\"upper-index\">9</sup></span>) โ coordinates of segment's beginning and end positions. The given segments can degenerate into points.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the word ยซ<span class=\"tex-font-style-tt\">YES</span>ยป, if the given four segments form the required rectangle, otherwise output ยซ<span class=\"tex-font-style-tt\">NO</span>ยป.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 6 1<br />1 0 6 0<br />6 0 6 1<br />1 1 1 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>0 0 0 3<br />2 0 0 0<br />2 2 2 0<br />0 2 2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:31</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" 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class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='0213eace8fc11974737662f82188969a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/slycelote\">slycelote</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/slycelote\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/slycelote\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/slycelote\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/slycelote\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/slycelote\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/slycelote\" style=\"text-decoration:none;color:black !important;\">slycelote's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"389\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/389\"> Codeforces Beta Round #14 tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a>,\r\n <span class=\"format-humantime\" title=\"May/20/2010 14:32\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"../../../contest/14/problem/A\">A. Letter </a></h3>To find the smallest rectangle containing the picture, iterate through the pairs (i,j) such that the j-th symbol in i-th line is '*'; find the minimum and maximum values of i and j from these pairs. The rectangle to output is <span class=\"tex-span\">[<i>i</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>i</i><sub class=\"lower-index\"><i>max</i></sub>]โรโ[<i>j</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>j</i><sub class=\"lower-index\"><i>max</i></sub>]</span>.<br /> <br /><h3><a href=\"../../../contest/14/problem/B\">B. Young Photographer </a></h3>First we find the intersection of all segments. To do this, denote by m the rightmost of left ends of the segments and denote by M the leftmost of right ends of the segments. The intersection of the segments is [m,M] (or empty set if m>M). Now determine the nearest point from this segment. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ<โ<i>m</i></span>, it's <span class=\"tex-span\"><i>m</i></span>, and the answer is <span class=\"tex-span\"><i>m</i>โ-โ<i>x</i><sub class=\"lower-index\">0</sub></span>. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ>โ<i>M</i></span>, it's <span class=\"tex-span\"><i>M</i></span>, and the answer is <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ-โ<i>M</i></span>. If <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/749c7b5acd626af9f654a7a9c45a7e72ae3739b1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, it's <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, and the answer is 0. If m>M, then the answer is -1.<br /><br /><h3><a href=\"../../../contest/14/problem/C\">C. Four Segments </a></h3>There must be many ways to solve this problem. The following one seems quite easy to code.<br />First count the number of distinct points among segments' ends. If it's not equal to 4, the segments can't form a rectangle and we output "NO". Then calculate the minimum and maximum coordinates of the 4 points: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>min</i></sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>max</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>min</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>max</i></sub></span>. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>min</i></sub>โ=โ<i>x</i><sub class=\"lower-index\"><i>max</i></sub></span> or <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>min</i></sub>โ=โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub></span>, then even if the segments form a rectangle, it has zero area, so we also output "NO" in this case.<br />Now if the segments indeed form a rectangle, we know the coordinates of its vertices โ <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>min</i></sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>max</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>min</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>max</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub>)</span>. We just check that every side of this rectangle appears in the input. If it is the case, we output "YES", otherwise we output "NO".<br /><br /><h3><a href=\"../../../contest/14/problem/D\">D. Two Paths </a></h3>Take any pair of non-intersecting paths. Since Flatland is connected, there must be a third path, connecting these two. Remove a road from the third path. Then Flatland is divided into two components โ one containing the first path, and the other containing the second path. This observation suggests us the algorithm: iterate over the roads; for each road remove it, find the longest path in both connected components and multiply the lengths of these paths. The longest path in a tree can be found by depth first search from each leaf. <br /><br /><h3><a href=\"../../../contest/14/problem/E\">E. Camels </a></h3>Let us call an index j such that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โโ>โโ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โโ<โโ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> a <i>cavity</i>. Also, we'll call humps and cavities by the common word <i>break</i>. Then there must be exactly <span class=\"tex-span\"><i>T</i>โ=โ2<i>t</i>โ-โ1</span> breaks, and the first one must be a hump.<br />Denote by <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span> the number of ways in which a camel with <span class=\"tex-span\"><i>t</i></span> breaks, ending at the point (n,h), can be extended to the end (the vertical <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>N</i></sub>โ=โ<i>N</i></span>) so that the total number of breaks was equal to T. Note that:<br />1. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>NTh</i></sub>โ=โ1</span>, if h=1,2,3,4. (We have already finished the camel and it has T breaks)<br />2. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>Nth</i></sub>โ=โ0</span>, if <span class=\"tex-span\">0โโคโ<i>t</i>โ<โ<i>T</i>,โ<i>h</i>โ=โ1,โ2,โ3,โ4</span>. (We have already finished the camel, but it has less than T breaks)<br />3. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>n</i>,โ<i>T</i>โ+โ1,โ<i>h</i></sub>โ=โ0</span>, if <span class=\"tex-span\">1โโคโ<i>n</i>โโคโ<i>N</i></span>, <span class=\"tex-span\"><i>h</i>โ=โ1,โ2,โ3,โ4</span>. (The camel has already more than T breaks).<br />ย <br />Now we find the recurrent formula for <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span>. Suppose that <span class=\"tex-span\"><i>t</i></span> is even. Then the last break was a cavity, and we are moving up currently. We can continue moving up, then the number of breaks stays the same, and we move to one of the points <span class=\"tex-span\">(<i>n</i>โ+โ1,โ<i>h</i>โ+โ1),โ(<i>n</i>โ+โ1,โ<i>h</i>โ+โ2),โ...,โ(<i>n</i>โ+โ1,โ4)</span>. Or we can move down, then the number of breaks increases by 1, and we move to one of the points <span class=\"tex-span\">(<i>n</i>โ+โ1,โ<i>h</i>โ-โ1),โ(<i>n</i>โ+โ1,โ<i>h</i>โ-โ2),โ...,โ(<i>n</i>โ+โ1,โ1)</span>. This gives us the formula<br /><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bb042e4d20db3f7b4c33498561e49dca993dcc6f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br /><br />If <span class=\"tex-span\"><i>t</i></span> is odd, then the last break was a hump, and similar reasoning leads to the formula<br /><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8fc933a174c005b52ffcb7abab83c0be0a45a020.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br /><br />We can calculate <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span> by dynamic programming. Consider now the point <span class=\"tex-span\">(2,โ<i>h</i>)</span> on a camel. There are h-1 ways to get to this point (starting from points <span class=\"tex-span\">(1,โ1),โ...,โ(1,โ<i>h</i>โ-โ1)</span>), and <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\">2,โ0,โ<i>h</i></sub></span> ways to extend the camel to the end. So the answer to the problem is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/354f45c5b67de98802fb5de9d46822d18922657e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/14\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 14 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-934-389\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"934\",\n blogEntryId: \"389\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2314\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #14</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-389\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+19</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-389\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/slycelote\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/slycelote\">\n slycelote\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/20/2010 14:32\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/389#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/389#comments\">\n 21\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"399\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5246\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MikeMirzayanov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11/avatar/e381f6b97eab28f0.jpg'/> </a>\n <div><a href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\" class=\"rated-user user-admin\">MikeMirzayanov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2010 15:05\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5246\" href=\"?#comment-5246\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5246\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5246\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Great tutorial, thanks!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5246 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5246 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5246\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5247\" commentParentId=\"5246\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2010 15:21\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5247\" href=\"?#comment-5247\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5246\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5247\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5247\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thank <i>you</i> for this awesome site! :)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5247 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5247 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5247\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5270\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 00:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5270\" href=\"?#comment-5270\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5270\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5270\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks for the tutorial. But in problem C how do I determine 4 distinct points?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5270 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5270 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5270\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5271\" commentParentId=\"5270\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 00:35\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5271\" href=\"?#comment-5271\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5270\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5271\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5271\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">For example, you can add all points to a set and then calculate its size.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5271 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5271 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5271\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5277\" commentParentId=\"5271\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 18:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5277\" href=\"?#comment-5277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5271\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Can anyone help me make a complex set in C++?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5277\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5280\" commentParentId=\"5277\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 18:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5280\" href=\"?#comment-5280\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5277\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5280\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5280\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What do you mean? Have you tried std::set?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5280 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5280 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5280\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5281\" commentParentId=\"5280\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 19:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5281\" href=\"?#comment-5281\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5280\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5281\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5281\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes. Here's how:<br /><br />typedef complex<int> point;<br />set<point> S;<br /><br />But it doesn't work. I can't insert any element using S.insert();</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5281 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5281 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5281\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5282\" commentParentId=\"5281\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 20:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5282\" href=\"?#comment-5282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5281\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">"I can't do that" is a bad diagnostic. You should at least post error message. Also, it's useful to read the message yourself.<br /><br />Anyway. std::complex cannot be used with std::set, because it doesn't define operator<. Write your own struct or use std::pair.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5282\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5284\" commentParentId=\"5282\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 22:10\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5284\" href=\"?#comment-5284\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5282\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5284\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5284\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I'm done! Thank you honorable Captain <b>adamax</b>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5284 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5284 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5284\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5272\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Harta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Harta\" title=\"Expert Harta\" class=\"rated-user user-blue\">Harta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 03:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5272\" href=\"?#comment-5272\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5272\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1765\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5272\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Nice tutorial. I like it so much. Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5272 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5272 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5272\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10499\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2010 19:42\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10499\" href=\"?#comment-10499\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10499\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10499\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><h3><a href=\"../../contest/14/problem/D\">D. Two Paths </a></h3>same question on spoj.pl but 2 โคย <em>N</em> โคย 100000 any idea how to solve.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10499 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10499 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10499\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10527\" commentParentId=\"10499\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10527\" href=\"?#comment-10527\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10499\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10527\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10527\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you post a link to the spoj problem?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10527 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10527 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10527\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10532\" commentParentId=\"10527\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2010 15:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10532\" href=\"?#comment-10532\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10527\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10532\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10532\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://www.spoj.pl/problems/TWOPATHS/</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10532 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10532 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10532\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"410937\" commentParentId=\"10532\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/nitishk24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/485797/avatar/617f3e8ef0883a39.jpg'/> </a>\n <div><a href=\"/profile/nitishk24\" title=\"Master nitishk24\" class=\"rated-user user-orange\">nitishk24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2018 01:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-410937\" href=\"?#comment-410937\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10532\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"410937\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"485797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-410937\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://www.quora.com/How-do-I-solve-SPOJ-Two-Paths-problem\">https://www.quora.com/How-do-I-solve-SPOJ-Two-Paths-problem</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-410937 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-410937 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-410937\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"410941\" commentParentId=\"410937\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/brdy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/660867/avatar/93b8b981d83e596f.jpg'/> </a>\n <div><a href=\"/profile/brdy\" title=\"Expert brdy\" class=\"rated-user user-blue\">brdy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2018 02:31\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-410941\" href=\"?#comment-410941\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-410937\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"410941\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"660867\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-410941\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>7 years late -_-</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-410941 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-410941 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-410941\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752291\" commentParentId=\"410941\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/TDung\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/588658/avatar/968daa2ee368eabb.jpg'/> </a>\n <div><a href=\"/profile/TDung\" title=\"Expert TDung\" class=\"rated-user user-blue\">TDung</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 17:09\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752291\" href=\"?#comment-752291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-410941\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"588658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>10 years late =))</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"592530\" commentParentId=\"10499\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/amiratou\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/678636/avatar/2daac9b72100e4eb.jpg'/> </a>\n <div><a href=\"/profile/amiratou\" title=\"Candidate Master amiratou\" class=\"rated-user user-violet\">amiratou</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/24/2020 22:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-592530\" href=\"?#comment-592530\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10499\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"592530\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"678636\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-592530\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I believe my solution runs in $$$O(n\\log{}n)$$$. There is a log factor because I am using sort(I believe I can get rid of it btw because I use it to pick the largest value and second-largest one in a vector). So in my solution, firstly I calculate the diameter of the tree using DP which means I obtain the answer for each node considering only nodes in its subtree in the tree rooted by an arbitrary node. Then, I use the rebooting technique of the tree following the order of the dfs. For each edge (u,v), I suppose it is cut and I calculate the diameter of the tree rooted by u but without the subtree rooted at v and since I have already calculated the diameter of the subtree rooted by v, I multiply these two values of diameters and keep the maximum result. Here is my code <a href=\"/contest/14/submission/74234280\" title=\"Submission 74234280 by amiratou\">74234280</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-592530 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-592530 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-592530\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"695975\" commentParentId=\"592530\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Peco\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1444856/avatar/1efcc387eb219f29.jpg'/> </a>\n <div><a href=\"/profile/Peco\" title=\"Master Peco\" class=\"rated-user user-orange\">Peco</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2020 18:30\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-695975\" href=\"?#comment-695975\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-592530\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"695975\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"695975\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1444856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-695975\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you keep the diameters of the subtrees and then you make an idea like rerooting: dp in-out, we can reduce it to $$$O(n)$$$ because in rerooting it would only change $$$O(deg (v))$$$ heights of nodes, right?</p><p>We can solve this when we remove the information from the child to some root, at that moment it is as if the edge does not exist.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-695975 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-695975 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-695975\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"239953\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yajun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/139743/avatar/b4f4ecad0fef6f50.jpg'/> </a>\n <div><a href=\"/profile/yajun\" title=\"Expert yajun\" class=\"rated-user user-blue\">yajun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/05/2015 15:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-239953\" href=\"?#comment-239953\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"239953\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"239953\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"139743\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-239953\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>About the solution of problem E.</p><p>The first one must be a hump, also ** the last one must be a hump.**</p><p>So, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>Nth</i></sub>โ=โ0,โ<i>if</i>0โโคโ<i>t</i>โ<โ<i>T</i>,โ<i>h</i>โ=โ1,โ2,โ3</span>.</p><p>BTW, when <span class=\"tex-span\"><i>N</i>โ+โ2โ<โ<i>T</i></span>, no camel with t humps exist, so the answer is 0.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-239953 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-239953 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-239953\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-399\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":62,"cells":{"problem_id":{"kind":"string","value":"14D"},"contest":{"kind":"string","value":"14"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Two Paths"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Two Paths</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>As you know, Bob's brother lives in Flatland. In Flatland there are <span class=\"tex-span\"><i>n</i></span> cities, connected by <span class=\"tex-span\"><i>n</i>โ-โ1</span> two-way roads. The cities are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>. You can get from one city to another moving along the roads.</p><p>The ยซTwo Pathsยป company, where Bob's brother works, has won a tender to repair two paths in Flatland. A path is a sequence of different cities, connected sequentially by roads. The company is allowed to choose by itself the paths to repair. The only condition they have to meet is that the two paths shouldn't cross (i.e. shouldn't have common cities).</p><p>It is known that the profit, the ยซTwo Pathsยป company will get, equals the product of the lengths of the two paths. Let's consider the length of each road equals 1, and the length of a path equals the amount of roads in it. Find the maximum possible profit for the company.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ200</span>), where <span class=\"tex-span\"><i>n</i></span> is the amount of cities in the country. The following <span class=\"tex-span\"><i>n</i>โ-โ1</span> lines contain the information about the roads. Each line contains a pair of numbers of the cities, connected by the road <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ<i>n</i></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the maximum possible profit.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>1 2<br/>2 3<br/>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br/>1 2<br/>1 3<br/>1 4<br/>1 5<br/>1 6<br/>1 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>1 2<br/>2 3<br/>2 4<br/>5 4<br/>6 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"05d6a562095499eae5899f196732d81c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"9cbc35cd4f0589a8d7b11e3fe4015811ce6ba465\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Two Paths</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>As you know, Bob's brother lives in Flatland. In Flatland there are <span class=\"tex-span\"><i>n</i></span> cities, connected by <span class=\"tex-span\"><i>n</i>โ-โ1</span> two-way roads. The cities are numbered from 1 to <span class=\"tex-span\"><i>n</i></span>. You can get from one city to another moving along the roads.</p><p>The ยซTwo Pathsยป company, where Bob's brother works, has won a tender to repair two paths in Flatland. A path is a sequence of different cities, connected sequentially by roads. The company is allowed to choose by itself the paths to repair. The only condition they have to meet is that the two paths shouldn't cross (i.e. shouldn't have common cities).</p><p>It is known that the profit, the ยซTwo Pathsยป company will get, equals the product of the lengths of the two paths. Let's consider the length of each road equals 1, and the length of a path equals the amount of roads in it. Find the maximum possible profit for the company.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains an integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ200</span>), where <span class=\"tex-span\"><i>n</i></span> is the amount of cities in the country. The following <span class=\"tex-span\"><i>n</i>โ-โ1</span> lines contain the information about the roads. Each line contains a pair of numbers of the cities, connected by the road <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ<i>n</i></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the maximum possible profit.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />1 2<br />2 3<br />3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br />1 2<br />1 3<br />1 4<br />1 5<br />1 6<br />1 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />1 2<br />2 3<br />2 4<br />5 4<br />6 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:31</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='0213eace8fc11974737662f82188969a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 โ Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/slycelote\">slycelote</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/slycelote\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/slycelote\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/slycelote\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/slycelote\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/slycelote\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/slycelote\" style=\"text-decoration:none;color:black !important;\">slycelote's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"389\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/389\"> Codeforces Beta Round #14 tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a>,\r\n <span class=\"format-humantime\" title=\"May/20/2010 14:32\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"../../../contest/14/problem/A\">A. Letter </a></h3>To find the smallest rectangle containing the picture, iterate through the pairs (i,j) such that the j-th symbol in i-th line is '*'; find the minimum and maximum values of i and j from these pairs. The rectangle to output is <span class=\"tex-span\">[<i>i</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>i</i><sub class=\"lower-index\"><i>max</i></sub>]โรโ[<i>j</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>j</i><sub class=\"lower-index\"><i>max</i></sub>]</span>.<br /> <br /><h3><a href=\"../../../contest/14/problem/B\">B. Young Photographer </a></h3>First we find the intersection of all segments. To do this, denote by m the rightmost of left ends of the segments and denote by M the leftmost of right ends of the segments. The intersection of the segments is [m,M] (or empty set if m>M). Now determine the nearest point from this segment. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ<โ<i>m</i></span>, it's <span class=\"tex-span\"><i>m</i></span>, and the answer is <span class=\"tex-span\"><i>m</i>โ-โ<i>x</i><sub class=\"lower-index\">0</sub></span>. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ>โ<i>M</i></span>, it's <span class=\"tex-span\"><i>M</i></span>, and the answer is <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ-โ<i>M</i></span>. If <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/749c7b5acd626af9f654a7a9c45a7e72ae3739b1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, it's <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, and the answer is 0. If m>M, then the answer is -1.<br /><br /><h3><a href=\"../../../contest/14/problem/C\">C. Four Segments </a></h3>There must be many ways to solve this problem. The following one seems quite easy to code.<br />First count the number of distinct points among segments' ends. If it's not equal to 4, the segments can't form a rectangle and we output "NO". Then calculate the minimum and maximum coordinates of the 4 points: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>min</i></sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>max</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>min</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>max</i></sub></span>. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>min</i></sub>โ=โ<i>x</i><sub class=\"lower-index\"><i>max</i></sub></span> or <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>min</i></sub>โ=โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub></span>, then even if the segments form a rectangle, it has zero area, so we also output "NO" in this case.<br />Now if the segments indeed form a rectangle, we know the coordinates of its vertices โ <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>min</i></sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>max</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>min</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>max</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub>)</span>. We just check that every side of this rectangle appears in the input. If it is the case, we output "YES", otherwise we output "NO".<br /><br /><h3><a href=\"../../../contest/14/problem/D\">D. Two Paths </a></h3>Take any pair of non-intersecting paths. Since Flatland is connected, there must be a third path, connecting these two. Remove a road from the third path. Then Flatland is divided into two components โ one containing the first path, and the other containing the second path. This observation suggests us the algorithm: iterate over the roads; for each road remove it, find the longest path in both connected components and multiply the lengths of these paths. The longest path in a tree can be found by depth first search from each leaf. <br /><br /><h3><a href=\"../../../contest/14/problem/E\">E. Camels </a></h3>Let us call an index j such that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โโ>โโ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โโ<โโ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> a <i>cavity</i>. Also, we'll call humps and cavities by the common word <i>break</i>. Then there must be exactly <span class=\"tex-span\"><i>T</i>โ=โ2<i>t</i>โ-โ1</span> breaks, and the first one must be a hump.<br />Denote by <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span> the number of ways in which a camel with <span class=\"tex-span\"><i>t</i></span> breaks, ending at the point (n,h), can be extended to the end (the vertical <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>N</i></sub>โ=โ<i>N</i></span>) so that the total number of breaks was equal to T. Note that:<br />1. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>NTh</i></sub>โ=โ1</span>, if h=1,2,3,4. (We have already finished the camel and it has T breaks)<br />2. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>Nth</i></sub>โ=โ0</span>, if <span class=\"tex-span\">0โโคโ<i>t</i>โ<โ<i>T</i>,โ<i>h</i>โ=โ1,โ2,โ3,โ4</span>. (We have already finished the camel, but it has less than T breaks)<br />3. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>n</i>,โ<i>T</i>โ+โ1,โ<i>h</i></sub>โ=โ0</span>, if <span class=\"tex-span\">1โโคโ<i>n</i>โโคโ<i>N</i></span>, <span class=\"tex-span\"><i>h</i>โ=โ1,โ2,โ3,โ4</span>. (The camel has already more than T breaks).<br />ย <br />Now we find the recurrent formula for <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span>. Suppose that <span class=\"tex-span\"><i>t</i></span> is even. Then the last break was a cavity, and we are moving up currently. We can continue moving up, then the number of breaks stays the same, and we move to one of the points <span class=\"tex-span\">(<i>n</i>โ+โ1,โ<i>h</i>โ+โ1),โ(<i>n</i>โ+โ1,โ<i>h</i>โ+โ2),โ...,โ(<i>n</i>โ+โ1,โ4)</span>. Or we can move down, then the number of breaks increases by 1, and we move to one of the points <span class=\"tex-span\">(<i>n</i>โ+โ1,โ<i>h</i>โ-โ1),โ(<i>n</i>โ+โ1,โ<i>h</i>โ-โ2),โ...,โ(<i>n</i>โ+โ1,โ1)</span>. This gives us the formula<br /><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bb042e4d20db3f7b4c33498561e49dca993dcc6f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br /><br />If <span class=\"tex-span\"><i>t</i></span> is odd, then the last break was a hump, and similar reasoning leads to the formula<br /><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8fc933a174c005b52ffcb7abab83c0be0a45a020.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br /><br />We can calculate <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span> by dynamic programming. Consider now the point <span class=\"tex-span\">(2,โ<i>h</i>)</span> on a camel. There are h-1 ways to get to this point (starting from points <span class=\"tex-span\">(1,โ1),โ...,โ(1,โ<i>h</i>โ-โ1)</span>), and <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\">2,โ0,โ<i>h</i></sub></span> ways to extend the camel to the end. So the answer to the problem is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/354f45c5b67de98802fb5de9d46822d18922657e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/14\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 14 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-934-389\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"934\",\n blogEntryId: \"389\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2314\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #14</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-389\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+19</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-389\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/slycelote\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/slycelote\">\n slycelote\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/20/2010 14:32\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/389#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/389#comments\">\n 21\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"399\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5246\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MikeMirzayanov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11/avatar/e381f6b97eab28f0.jpg'/> </a>\n <div><a href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\" class=\"rated-user user-admin\">MikeMirzayanov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2010 15:05\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5246\" href=\"?#comment-5246\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5246\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5246\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Great tutorial, thanks!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5246 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5246 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5246\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5247\" commentParentId=\"5246\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2010 15:21\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5247\" href=\"?#comment-5247\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5246\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5247\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5247\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thank <i>you</i> for this awesome site! :)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5247 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5247 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5247\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5270\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 00:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5270\" href=\"?#comment-5270\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5270\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5270\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks for the tutorial. But in problem C how do I determine 4 distinct points?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5270 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5270 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5270\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5271\" commentParentId=\"5270\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 00:35\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5271\" href=\"?#comment-5271\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5270\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5271\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5271\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">For example, you can add all points to a set and then calculate its size.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5271 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5271 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5271\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5277\" commentParentId=\"5271\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 18:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5277\" href=\"?#comment-5277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5271\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Can anyone help me make a complex set in C++?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5277\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5280\" commentParentId=\"5277\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 18:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5280\" href=\"?#comment-5280\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5277\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5280\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5280\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What do you mean? Have you tried std::set?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5280 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5280 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5280\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5281\" commentParentId=\"5280\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 19:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5281\" href=\"?#comment-5281\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5280\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5281\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5281\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes. Here's how:<br /><br />typedef complex<int> point;<br />set<point> S;<br /><br />But it doesn't work. I can't insert any element using S.insert();</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5281 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5281 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5281\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5282\" commentParentId=\"5281\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 20:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5282\" href=\"?#comment-5282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5281\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">"I can't do that" is a bad diagnostic. You should at least post error message. Also, it's useful to read the message yourself.<br /><br />Anyway. std::complex cannot be used with std::set, because it doesn't define operator<. Write your own struct or use std::pair.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5282\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5284\" commentParentId=\"5282\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 22:10\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5284\" href=\"?#comment-5284\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5282\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5284\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5284\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I'm done! Thank you honorable Captain <b>adamax</b>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5284 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5284 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5284\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5272\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Harta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Harta\" title=\"Expert Harta\" class=\"rated-user user-blue\">Harta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 03:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5272\" href=\"?#comment-5272\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5272\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1765\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5272\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Nice tutorial. I like it so much. Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5272 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5272 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5272\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10499\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2010 19:42\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10499\" href=\"?#comment-10499\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10499\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10499\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><h3><a href=\"../../contest/14/problem/D\">D. Two Paths </a></h3>same question on spoj.pl but 2 โคย <em>N</em> โคย 100000 any idea how to solve.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10499 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10499 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10499\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10527\" commentParentId=\"10499\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10527\" href=\"?#comment-10527\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10499\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10527\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10527\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you post a link to the spoj problem?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10527 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10527 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10527\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10532\" commentParentId=\"10527\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2010 15:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10532\" href=\"?#comment-10532\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10527\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10532\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10532\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://www.spoj.pl/problems/TWOPATHS/</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10532 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10532 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10532\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"410937\" commentParentId=\"10532\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/nitishk24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/485797/avatar/617f3e8ef0883a39.jpg'/> </a>\n <div><a href=\"/profile/nitishk24\" title=\"Master nitishk24\" class=\"rated-user user-orange\">nitishk24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2018 01:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-410937\" href=\"?#comment-410937\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10532\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"410937\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"485797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-410937\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://www.quora.com/How-do-I-solve-SPOJ-Two-Paths-problem\">https://www.quora.com/How-do-I-solve-SPOJ-Two-Paths-problem</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-410937 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-410937 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-410937\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"410941\" commentParentId=\"410937\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/brdy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/660867/avatar/93b8b981d83e596f.jpg'/> </a>\n <div><a href=\"/profile/brdy\" title=\"Expert brdy\" class=\"rated-user user-blue\">brdy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2018 02:31\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-410941\" href=\"?#comment-410941\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-410937\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"410941\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"660867\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-410941\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>7 years late -_-</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-410941 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-410941 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-410941\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752291\" commentParentId=\"410941\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/TDung\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/588658/avatar/968daa2ee368eabb.jpg'/> </a>\n <div><a href=\"/profile/TDung\" title=\"Expert TDung\" class=\"rated-user user-blue\">TDung</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 17:09\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752291\" href=\"?#comment-752291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-410941\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"588658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>10 years late =))</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"592530\" commentParentId=\"10499\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/amiratou\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/678636/avatar/2daac9b72100e4eb.jpg'/> </a>\n <div><a href=\"/profile/amiratou\" title=\"Candidate Master amiratou\" class=\"rated-user user-violet\">amiratou</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/24/2020 22:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-592530\" href=\"?#comment-592530\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10499\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"592530\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"678636\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-592530\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I believe my solution runs in $$$O(n\\log{}n)$$$. There is a log factor because I am using sort(I believe I can get rid of it btw because I use it to pick the largest value and second-largest one in a vector). So in my solution, firstly I calculate the diameter of the tree using DP which means I obtain the answer for each node considering only nodes in its subtree in the tree rooted by an arbitrary node. Then, I use the rebooting technique of the tree following the order of the dfs. For each edge (u,v), I suppose it is cut and I calculate the diameter of the tree rooted by u but without the subtree rooted at v and since I have already calculated the diameter of the subtree rooted by v, I multiply these two values of diameters and keep the maximum result. Here is my code <a href=\"/contest/14/submission/74234280\" title=\"Submission 74234280 by amiratou\">74234280</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-592530 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-592530 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-592530\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"695975\" commentParentId=\"592530\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Peco\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1444856/avatar/1efcc387eb219f29.jpg'/> </a>\n <div><a href=\"/profile/Peco\" title=\"Master Peco\" class=\"rated-user user-orange\">Peco</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2020 18:30\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-695975\" href=\"?#comment-695975\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-592530\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"695975\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"695975\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1444856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-695975\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you keep the diameters of the subtrees and then you make an idea like rerooting: dp in-out, we can reduce it to $$$O(n)$$$ because in rerooting it would only change $$$O(deg (v))$$$ heights of nodes, right?</p><p>We can solve this when we remove the information from the child to some root, at that moment it is as if the edge does not exist.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-695975 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-695975 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-695975\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"239953\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yajun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/139743/avatar/b4f4ecad0fef6f50.jpg'/> </a>\n <div><a href=\"/profile/yajun\" title=\"Expert yajun\" class=\"rated-user user-blue\">yajun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/05/2015 15:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-239953\" href=\"?#comment-239953\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"239953\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"239953\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"139743\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-239953\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>About the solution of problem E.</p><p>The first one must be a hump, also ** the last one must be a hump.**</p><p>So, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>Nth</i></sub>โ=โ0,โ<i>if</i>0โโคโ<i>t</i>โ<โ<i>T</i>,โ<i>h</i>โ=โ1,โ2,โ3</span>.</p><p>BTW, when <span class=\"tex-span\"><i>N</i>โ+โ2โ<โ<i>T</i></span>, no camel with t humps exist, so the answer is 0.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-239953 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-239953 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-239953\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-399\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div 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Camels"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Camels</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob likes to draw camels: with a single hump, two humps, three humps, etc. He draws a camel by connecting points on a coordinate plane. Now he's drawing camels with <span class=\"tex-span\"><i>t</i></span> humps, representing them as polylines in the plane. Each polyline consists of <span class=\"tex-span\"><i>n</i></span> vertices with coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>)</span>, ..., <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>n</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. The first vertex has a coordinate <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>โ=โ1</span>, the second โ <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub>โ=โ2</span>, etc. Coordinates <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> might be any, but should satisfy the following conditions:</p><ul> <li> there should be <span class=\"tex-span\"><i>t</i></span> humps precisely, i.e. such indexes <span class=\"tex-span\"><i>j</i></span> (<span class=\"tex-span\">2โโคโ<i>j</i>โโคโ<i>n</i>โ-โ1</span>), so that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โ<โ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โ>โ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span>, </li><li> there should be precisely <span class=\"tex-span\"><i>t</i>โ-โ1</span> such indexes <span class=\"tex-span\"><i>j</i></span> (<span class=\"tex-span\">2โโคโ<i>j</i>โโคโ<i>n</i>โ-โ1</span>), so that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โ>โ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โ<โ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span>, </li><li> no segment of a polyline should be parallel to the <span class=\"tex-span\"><i>Ox</i></span>-axis, </li><li> all <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> are integers between 1 and 4. </li></ul><p>For a series of his drawings of camels with <span class=\"tex-span\"><i>t</i></span> humps Bob wants to buy a notebook, but he doesn't know how many pages he will need. Output the amount of different polylines that can be drawn to represent camels with <span class=\"tex-span\"><i>t</i></span> humps for a given number <span class=\"tex-span\"><i>n</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a pair of integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">3โโคโ<i>n</i>โโคโ20</span>, <span class=\"tex-span\">1โโคโ<i>t</i>โโคโ10</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the required amount of camels with <span class=\"tex-span\"><i>t</i></span> humps.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample test sequences of <span class=\"tex-span\"><i>y</i></span>-coordinates for six camels are: 123421, 123431, 123432, 124321, 134321 ะธ 234321 (each digit corresponds to one value of <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span>).</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"7252f0f731c1cff180aedfd7f4956611\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"9cbc35cd4f0589a8d7b11e3fe4015811ce6ba465\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"header\"><div class=\"title\">E. Camels</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob likes to draw camels: with a single hump, two humps, three humps, etc. He draws a camel by connecting points on a coordinate plane. Now he's drawing camels with <span class=\"tex-span\"><i>t</i></span> humps, representing them as polylines in the plane. Each polyline consists of <span class=\"tex-span\"><i>n</i></span> vertices with coordinates <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>)</span>, ..., <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>n</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>n</i></sub>)</span>. The first vertex has a coordinate <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>โ=โ1</span>, the second โ <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub>โ=โ2</span>, etc. Coordinates <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> might be any, but should satisfy the following conditions:</p><ul> <li> there should be <span class=\"tex-span\"><i>t</i></span> humps precisely, i.e. such indexes <span class=\"tex-span\"><i>j</i></span> (<span class=\"tex-span\">2โโคโ<i>j</i>โโคโ<i>n</i>โ-โ1</span>), so that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โ<โ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โ>โ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span>, </li><li> there should be precisely <span class=\"tex-span\"><i>t</i>โ-โ1</span> such indexes <span class=\"tex-span\"><i>j</i></span> (<span class=\"tex-span\">2โโคโ<i>j</i>โโคโ<i>n</i>โ-โ1</span>), so that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โ>โ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โ<โ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span>, </li><li> no segment of a polyline should be parallel to the <span class=\"tex-span\"><i>Ox</i></span>-axis, </li><li> all <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> are integers between 1 and 4. </li></ul><p>For a series of his drawings of camels with <span class=\"tex-span\"><i>t</i></span> humps Bob wants to buy a notebook, but he doesn't know how many pages he will need. Output the amount of different polylines that can be drawn to represent camels with <span class=\"tex-span\"><i>t</i></span> humps for a given number <span class=\"tex-span\"><i>n</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains a pair of integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">3โโคโ<i>n</i>โโคโ20</span>, <span class=\"tex-span\">1โโคโ<i>t</i>โโคโ10</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the required amount of camels with <span class=\"tex-span\"><i>t</i></span> humps.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample test sequences of <span class=\"tex-span\"><i>y</i></span>-coordinates for six camels are: 123421, 123431, 123432, 124321, 134321 ะธ 234321 (each digit corresponds to one value of <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span>).</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:31</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='0213eace8fc11974737662f82188969a'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 โ Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/slycelote\">slycelote</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/slycelote\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/slycelote\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/slycelote\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/slycelote\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/slycelote\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/slycelote\" style=\"text-decoration:none;color:black !important;\">slycelote's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"389\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/389\"> Codeforces Beta Round #14 tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a>,\r\n <span class=\"format-humantime\" title=\"May/20/2010 14:32\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3><a href=\"../../../contest/14/problem/A\">A. Letter </a></h3>To find the smallest rectangle containing the picture, iterate through the pairs (i,j) such that the j-th symbol in i-th line is '*'; find the minimum and maximum values of i and j from these pairs. The rectangle to output is <span class=\"tex-span\">[<i>i</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>i</i><sub class=\"lower-index\"><i>max</i></sub>]โรโ[<i>j</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>j</i><sub class=\"lower-index\"><i>max</i></sub>]</span>.<br /> <br /><h3><a href=\"../../../contest/14/problem/B\">B. Young Photographer </a></h3>First we find the intersection of all segments. To do this, denote by m the rightmost of left ends of the segments and denote by M the leftmost of right ends of the segments. The intersection of the segments is [m,M] (or empty set if m>M). Now determine the nearest point from this segment. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ<โ<i>m</i></span>, it's <span class=\"tex-span\"><i>m</i></span>, and the answer is <span class=\"tex-span\"><i>m</i>โ-โ<i>x</i><sub class=\"lower-index\">0</sub></span>. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ>โ<i>M</i></span>, it's <span class=\"tex-span\"><i>M</i></span>, and the answer is <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub>โ-โ<i>M</i></span>. If <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/749c7b5acd626af9f654a7a9c45a7e72ae3739b1.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />, it's <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">0</sub></span>, and the answer is 0. If m>M, then the answer is -1.<br /><br /><h3><a href=\"../../../contest/14/problem/C\">C. Four Segments </a></h3>There must be many ways to solve this problem. The following one seems quite easy to code.<br />First count the number of distinct points among segments' ends. If it's not equal to 4, the segments can't form a rectangle and we output "NO". Then calculate the minimum and maximum coordinates of the 4 points: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>min</i></sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>max</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>min</i></sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>max</i></sub></span>. If <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>min</i></sub>โ=โ<i>x</i><sub class=\"lower-index\"><i>max</i></sub></span> or <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>min</i></sub>โ=โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub></span>, then even if the segments form a rectangle, it has zero area, so we also output "NO" in this case.<br />Now if the segments indeed form a rectangle, we know the coordinates of its vertices โ <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>min</i></sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>min</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub>)</span>, <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>max</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>min</i></sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\"><i>max</i></sub>,โ<i>y</i><sub class=\"lower-index\"><i>max</i></sub>)</span>. We just check that every side of this rectangle appears in the input. If it is the case, we output "YES", otherwise we output "NO".<br /><br /><h3><a href=\"../../../contest/14/problem/D\">D. Two Paths </a></h3>Take any pair of non-intersecting paths. Since Flatland is connected, there must be a third path, connecting these two. Remove a road from the third path. Then Flatland is divided into two components โ one containing the first path, and the other containing the second path. This observation suggests us the algorithm: iterate over the roads; for each road remove it, find the longest path in both connected components and multiply the lengths of these paths. The longest path in a tree can be found by depth first search from each leaf. <br /><br /><h3><a href=\"../../../contest/14/problem/E\">E. Camels </a></h3>Let us call an index j such that <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>j</i>โ-โ1</sub>โโ>โโ<i>y</i><sub class=\"lower-index\"><i>j</i></sub>โโ<โโ<i>y</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> a <i>cavity</i>. Also, we'll call humps and cavities by the common word <i>break</i>. Then there must be exactly <span class=\"tex-span\"><i>T</i>โ=โ2<i>t</i>โ-โ1</span> breaks, and the first one must be a hump.<br />Denote by <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span> the number of ways in which a camel with <span class=\"tex-span\"><i>t</i></span> breaks, ending at the point (n,h), can be extended to the end (the vertical <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>N</i></sub>โ=โ<i>N</i></span>) so that the total number of breaks was equal to T. Note that:<br />1. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>NTh</i></sub>โ=โ1</span>, if h=1,2,3,4. (We have already finished the camel and it has T breaks)<br />2. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>Nth</i></sub>โ=โ0</span>, if <span class=\"tex-span\">0โโคโ<i>t</i>โ<โ<i>T</i>,โ<i>h</i>โ=โ1,โ2,โ3,โ4</span>. (We have already finished the camel, but it has less than T breaks)<br />3. <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>n</i>,โ<i>T</i>โ+โ1,โ<i>h</i></sub>โ=โ0</span>, if <span class=\"tex-span\">1โโคโ<i>n</i>โโคโ<i>N</i></span>, <span class=\"tex-span\"><i>h</i>โ=โ1,โ2,โ3,โ4</span>. (The camel has already more than T breaks).<br />ย <br />Now we find the recurrent formula for <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span>. Suppose that <span class=\"tex-span\"><i>t</i></span> is even. Then the last break was a cavity, and we are moving up currently. We can continue moving up, then the number of breaks stays the same, and we move to one of the points <span class=\"tex-span\">(<i>n</i>โ+โ1,โ<i>h</i>โ+โ1),โ(<i>n</i>โ+โ1,โ<i>h</i>โ+โ2),โ...,โ(<i>n</i>โ+โ1,โ4)</span>. Or we can move down, then the number of breaks increases by 1, and we move to one of the points <span class=\"tex-span\">(<i>n</i>โ+โ1,โ<i>h</i>โ-โ1),โ(<i>n</i>โ+โ1,โ<i>h</i>โ-โ2),โ...,โ(<i>n</i>โ+โ1,โ1)</span>. This gives us the formula<br /><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/bb042e4d20db3f7b4c33498561e49dca993dcc6f.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br /><br />If <span class=\"tex-span\"><i>t</i></span> is odd, then the last break was a hump, and similar reasoning leads to the formula<br /><img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/8fc933a174c005b52ffcb7abab83c0be0a45a020.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.<br /><br />We can calculate <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>nth</i></sub></span> by dynamic programming. Consider now the point <span class=\"tex-span\">(2,โ<i>h</i>)</span> on a camel. There are h-1 ways to get to this point (starting from points <span class=\"tex-span\">(1,โ1),โ...,โ(1,โ<i>h</i>โ-โ1)</span>), and <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\">2,โ0,โ<i>h</i></sub></span> ways to extend the camel to the end. So the answer to the problem is <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/354f45c5b67de98802fb5de9d46822d18922657e.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/14\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 14 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-934-389\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"934\",\n blogEntryId: \"389\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2314\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #14</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-389\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+19</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-389\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/slycelote\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/slycelote\">\n slycelote\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/20/2010 14:32\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/389#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/389#comments\">\n 21\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"399\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5246\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MikeMirzayanov\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/11/avatar/e381f6b97eab28f0.jpg'/> </a>\n <div><a href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\" class=\"rated-user user-admin\">MikeMirzayanov</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2010 15:05\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5246\" href=\"?#comment-5246\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5246\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"11\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5246\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Great tutorial, thanks!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5246 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5246 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5246\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5247\" commentParentId=\"5246\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/20/2010 15:21\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5247\" href=\"?#comment-5247\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5246\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5247\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"12\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+12</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5247\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thank <i>you</i> for this awesome site! :)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5247 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5247 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5247\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5270\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 00:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5270\" href=\"?#comment-5270\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5270\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5270\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks for the tutorial. But in problem C how do I determine 4 distinct points?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5270 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5270 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5270\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5271\" commentParentId=\"5270\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 00:35\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5271\" href=\"?#comment-5271\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5270\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5271\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5271\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">For example, you can add all points to a set and then calculate its size.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5271 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5271 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5271\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5277\" commentParentId=\"5271\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 18:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5277\" href=\"?#comment-5277\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5271\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5277\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5277\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Can anyone help me make a complex set in C++?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5277 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5277 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5277\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5280\" commentParentId=\"5277\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 18:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5280\" href=\"?#comment-5280\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5277\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5280\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5280\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What do you mean? Have you tried std::set?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5280 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5280 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5280\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5281\" commentParentId=\"5280\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 19:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5281\" href=\"?#comment-5281\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5280\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5281\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5281\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes. Here's how:<br /><br />typedef complex<int> point;<br />set<point> S;<br /><br />But it doesn't work. I can't insert any element using S.insert();</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5281 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5281 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5281\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5282\" commentParentId=\"5281\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 20:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5282\" href=\"?#comment-5282\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5281\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5282\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5282\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">"I can't do that" is a bad diagnostic. You should at least post error message. Also, it's useful to read the message yourself.<br /><br />Anyway. std::complex cannot be used with std::set, because it doesn't define operator<. Write your own struct or use std::pair.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5282 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5282 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5282\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5284\" commentParentId=\"5282\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/f.nasim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/f.nasim\" title=\"Specialist f.nasim\" class=\"rated-user user-cyan\">f.nasim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 22:10\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5284\" href=\"?#comment-5284\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5282\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5284\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3052\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5284\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I'm done! Thank you honorable Captain <b>adamax</b>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5284 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5284 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5284\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5272\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Harta\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Harta\" title=\"Expert Harta\" class=\"rated-user user-blue\">Harta</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/22/2010 03:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5272\" href=\"?#comment-5272\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5272\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1765\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5272\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Nice tutorial. I like it so much. Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5272 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5272 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5272\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10499\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/13/2010 19:42\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10499\" href=\"?#comment-10499\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10499\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10499\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><h3><a href=\"../../contest/14/problem/D\">D. Two Paths </a></h3>same question on spoj.pl but 2 โคย <em>N</em> โคย 100000 any idea how to solve.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10499 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10499 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10499\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10527\" commentParentId=\"10499\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10527\" href=\"?#comment-10527\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10499\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10527\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10527\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you post a link to the spoj problem?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10527 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10527 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10527\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10532\" commentParentId=\"10527\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2010 15:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10532\" href=\"?#comment-10532\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10527\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10532\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10532\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://www.spoj.pl/problems/TWOPATHS/</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10532 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10532 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10532\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"410937\" commentParentId=\"10532\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/nitishk24\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/485797/avatar/617f3e8ef0883a39.jpg'/> </a>\n <div><a href=\"/profile/nitishk24\" title=\"Master nitishk24\" class=\"rated-user user-orange\">nitishk24</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2018 01:48\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-410937\" href=\"?#comment-410937\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10532\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"410937\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"485797\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-410937\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a href=\"https://www.quora.com/How-do-I-solve-SPOJ-Two-Paths-problem\">https://www.quora.com/How-do-I-solve-SPOJ-Two-Paths-problem</a></p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-410937 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-410937 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-410937\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"410941\" commentParentId=\"410937\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/brdy\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/660867/avatar/93b8b981d83e596f.jpg'/> </a>\n <div><a href=\"/profile/brdy\" title=\"Expert brdy\" class=\"rated-user user-blue\">brdy</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/31/2018 02:31\">6 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-410941\" href=\"?#comment-410941\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-410937\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"410941\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"660867\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-410941\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>7 years late -_-</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-410941 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-410941 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-410941\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"752291\" commentParentId=\"410941\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/TDung\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/588658/avatar/968daa2ee368eabb.jpg'/> </a>\n <div><a href=\"/profile/TDung\" title=\"Expert TDung\" class=\"rated-user user-blue\">TDung</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/24/2021 17:09\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-752291\" href=\"?#comment-752291\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-410941\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"752291\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"588658\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-752291\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>10 years late =))</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-752291 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-752291 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-752291\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"592530\" commentParentId=\"10499\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/amiratou\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/678636/avatar/2daac9b72100e4eb.jpg'/> </a>\n <div><a href=\"/profile/amiratou\" title=\"Candidate Master amiratou\" class=\"rated-user user-violet\">amiratou</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/24/2020 22:31\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-592530\" href=\"?#comment-592530\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-10499\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"592530\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"678636\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-592530\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I believe my solution runs in $$$O(n\\log{}n)$$$. There is a log factor because I am using sort(I believe I can get rid of it btw because I use it to pick the largest value and second-largest one in a vector). So in my solution, firstly I calculate the diameter of the tree using DP which means I obtain the answer for each node considering only nodes in its subtree in the tree rooted by an arbitrary node. Then, I use the rebooting technique of the tree following the order of the dfs. For each edge (u,v), I suppose it is cut and I calculate the diameter of the tree rooted by u but without the subtree rooted at v and since I have already calculated the diameter of the subtree rooted by v, I multiply these two values of diameters and keep the maximum result. Here is my code <a href=\"/contest/14/submission/74234280\" title=\"Submission 74234280 by amiratou\">74234280</a>.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-592530 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-592530 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-592530\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"695975\" commentParentId=\"592530\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Peco\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1444856/avatar/1efcc387eb219f29.jpg'/> </a>\n <div><a href=\"/profile/Peco\" title=\"Master Peco\" class=\"rated-user user-orange\">Peco</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/14/2020 18:30\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-695975\" href=\"?#comment-695975\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-592530\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"695975\" revisionCount=\"3\" revision=\"3\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">3</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"695975\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1444856\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-695975\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you keep the diameters of the subtrees and then you make an idea like rerooting: dp in-out, we can reduce it to $$$O(n)$$$ because in rerooting it would only change $$$O(deg (v))$$$ heights of nodes, right?</p><p>We can solve this when we remove the information from the child to some root, at that moment it is as if the edge does not exist.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-695975 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-695975 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-695975\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"239953\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/yajun\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/139743/avatar/b4f4ecad0fef6f50.jpg'/> </a>\n <div><a href=\"/profile/yajun\" title=\"Expert yajun\" class=\"rated-user user-blue\">yajun</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/05/2015 15:05\">8 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-239953\" href=\"?#comment-239953\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"239953\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"239953\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"139743\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-239953\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>About the solution of problem E.</p><p>The first one must be a hump, also ** the last one must be a hump.**</p><p>So, <span class=\"tex-span\"><i>f</i><sub class=\"lower-index\"><i>Nth</i></sub>โ=โ0,โ<i>if</i>0โโคโ<i>t</i>โ<โ<i>T</i>,โ<i>h</i>โ=โ1,โ2,โ3</span>.</p><p>BTW, when <span class=\"tex-span\"><i>N</i>โ+โ2โ<โ<i>T</i></span>, no camel with t humps exist, so the answer is 0.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-239953 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-239953 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-239953\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-399\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div 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Cottage Village"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Cottage Village</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A new cottage village called ยซFlatvilleยป is being built in Flatland. By now they have already built in ยซFlatvilleยป <span class=\"tex-span\"><i>n</i></span> square houses with the centres on the <span class=\"tex-span\"><i>ะx</i></span>-axis. The houses' sides are parallel to the coordinate axes. It's known that no two houses overlap, but they can touch each other.</p><p>The architect bureau, where Peter works, was commissioned to build a new house in ยซFlatvilleยป. The customer wants his future house to be on the <span class=\"tex-span\"><i>ะx</i></span>-axis, to be square in shape, have a side <span class=\"tex-span\"><i>t</i></span>, and touch at least one of the already built houses. For sure, its sides should be parallel to the coordinate axes, its centre should be on the <span class=\"tex-span\"><i>Ox</i></span>-axis and it shouldn't overlap any of the houses in the village.</p><p>Peter was given a list of all the houses in ยซFlatvilleยป. Would you help him find the amount of possible positions of the new house?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input data contains numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>t</i>โโคโ1000</span>). Then there follow <span class=\"tex-span\"><i>n</i></span> lines, each of them contains two space-separated integer numbers: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> โ <span class=\"tex-span\"><i>x</i></span>-coordinate of the centre of the <span class=\"tex-span\"><i>i</i></span>-th house, and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> โ length of its side (<span class=\"tex-span\">โ-โ1000โโคโ<i>x</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ1000</span>, <span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ1000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the amount of possible positions of the new house.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/>0 4<br/>6 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br/>0 4<br/>5 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3<br/>0 4<br/>5 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>It is possible for the <span class=\"tex-span\"><i>x</i></span>-coordinate of the new house to have non-integer value.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"12c91f5917523cfebe16d72dfb10ea65\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b52ce3cbb5b288ae3ade962da7b9abdbaf953f75\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"delete-resource-link\" resourceIds=\"439\" resourceName=\"ะะพัะพัะบะธะน ัะฐะทะฑะพั ะทะฐะดะฐั CF #15\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/419\" title=\"Codeforces Beta #15 Tutorial (Incomplete)\" target=\"_blank\">Tutorial #2 <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"705\" resourceName=\"Codeforces Beta #15 Tutorial (Incomplete)\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div 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'))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_ea0b6dd76a7c9c029439d3b420ddd3574d9b01ae\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Cottage Village</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A new cottage village called ยซFlatvilleยป is being built in Flatland. By now they have already built in ยซFlatvilleยป <span class=\"tex-span\"><i>n</i></span> square houses with the centres on the <span class=\"tex-span\"><i>ะx</i></span>-axis. The houses' sides are parallel to the coordinate axes. It's known that no two houses overlap, but they can touch each other.</p><p>The architect bureau, where Peter works, was commissioned to build a new house in ยซFlatvilleยป. The customer wants his future house to be on the <span class=\"tex-span\"><i>ะx</i></span>-axis, to be square in shape, have a side <span class=\"tex-span\"><i>t</i></span>, and touch at least one of the already built houses. For sure, its sides should be parallel to the coordinate axes, its centre should be on the <span class=\"tex-span\"><i>Ox</i></span>-axis and it shouldn't overlap any of the houses in the village.</p><p>Peter was given a list of all the houses in ยซFlatvilleยป. Would you help him find the amount of possible positions of the new house?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input data contains numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>t</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>t</i>โโคโ1000</span>). Then there follow <span class=\"tex-span\"><i>n</i></span> lines, each of them contains two space-separated integer numbers: <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, where <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> โ <span class=\"tex-span\"><i>x</i></span>-coordinate of the centre of the <span class=\"tex-span\"><i>i</i></span>-th house, and <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> โ length of its side (<span class=\"tex-span\">โ-โ1000โโคโ<i>x</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ1000</span>, <span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ1000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the amount of possible positions of the new house.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br />0 4<br />6 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 2<br />0 4<br />5 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3<br />0 4<br />5 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>It is possible for the <span class=\"tex-span\"><i>x</i></span>-coordinate of the new house to have non-integer value.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='526752e7c14b5be5b9bfaea946f6b2d1'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a 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style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! 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Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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href=\"/profile/Shtrix\">Shtrix</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Shtrix\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Shtrix\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Shtrix\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Shtrix\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Shtrix\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Shtrix\" style=\"text-decoration:none;color:black !important;\">Shtrix's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"411\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/411\"> ะะพัะพัะบะธะน ัะฐะทะฑะพั ะทะฐะดะฐั CF #15\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Shtrix\" title=\"Candidate Master Shtrix\" class=\"rated-user user-violet\">Shtrix</a>,\r\n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" alt=\"In Russian\" title=\"In Russian\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\">ะ) ย ย ย ย ย ะะตะพะฑั
ะพะดะธะผะพ ะฑัะปะพ ะพััะพััะธัะพะฒะฐัั ะฒัะต ะดะพะผะฐ ะฟะพ ะฒะพะทัะฐััะฐะฝะธั ะบะพะพัะดะธะฝะฐัั ัะตะฝััะฐ ั
. ะะปั ะบะฐะถะดะพะน ะฟะฐัั ะฟะพัะปะตะดะพะฒะฐัะตะปัะฝัั
ะดะพะผะพะฒ (x_i, a_i) ะธ (x_(i+1), a_(i+1)) ะพะฟัะตะดะตะปะธัั ัะฐัััะพัะฝะธะต ะผะตะถะดั ะดะพะผะฐะผะธ:</div><div style=\"text-align: left;\">d = x_(i + 1) - x_i + a_(i+1) / 2 + a_i / 2;</div><div style=\"text-align: left;\">ะตัะปะธ d > T ัะพ ans = ans + 2</div><div style=\"text-align: left;\">ะตัะปะธ d == T ัะพ ans = ans + 1</div><div style=\"text-align: left;\">ะธะฝะฐัะต ะฝะธัะตะณะพ ะฝะต ะดะตะปะฐะตะผ</div><div>ะฒ ะบะพะฝัะต ะบ ะพัะฒะตัั ะฝัะถะฝะพ ะฑัะปะพ ะดะพะฑะฐะฒะธัั ะดะฒะฐ, ััะพะฑั ะตัะต ะทะฐะบัััั ะบัะฐะนะฝะธะต ะฟะพะทะธัะธะธ.</div><div><br /></div><div>B) ย ย ย ย ย ย ะะปั ะฟัะพััะพัั ะฝะฐะฟะธัะฐะฝะธั, ะฝัะถะฝะพ ะฑัะปะพ ะทะฐะผะตัะธัั, ััะพ ะณะตะพะผะตััะธัะตัะบะพะต ะผะตััะพ ัะพัะตะบ ะบะพัะพััะต ะผะพะถะฝะพ ะฒัะถะตัั ะปะฐะทะตัะพะผ ััะพ ะดะฒะฐ ะฟััะผะพัะณะพะปัะฝะธะบะฐ. ะััะฐะฒะฐะปะพัั ัะพะปัะบะพ ะฟะพััะธัะฐัั ะธั
ััะผะผะฐัะฝัั ะฟะปะพัะฐะดั, ััะพ ะดะตะปะฐะตััั ะพัะตะฝั ะฟัะพััะพ ะฟะพ ัะพัะผัะปะต ะฒะบะปััะตะฝะธั-ะธัะบะปััะตะฝะธั. ะ ะฝะต ะทะฐะฑัะดััะต ะฟัะพ 64 ะฑะธัะฝะพะต ัะตะปะพะต!</div><div><br /></div><div>ะก) ย ย ย ย ย ย ะัะต ัะฐะท ะธะทะฒะธะฝัััั ะทะฐ ะพัะธะฑะบั ะฒ ะพะฟะธัะฐะฝะธะธ ะฒั
ะพะดะฐ. ะัะพัะธัะฐะฒ ะฝะตะผะฝะพะณะพ ะผะฐัะตัะธะฐะปะฐ ะฟะพ ัะตะพัะธะธ ะธะณั ะธ ัะธัะปะฐะผ <a href=\"https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D1%8F_%D0%A8%D0%BF%D1%80%D0%B0%D0%B3%D0%B0-%D0%93%D1%80%D0%B0%D0%BD%D0%B4%D0%B8\">ะจะฟัะฐะณะฐ ะัะฐะฝะดะธ</a>ย ะฒะฐะผ ััะฐะฝะตั ะพัะตะฒะธะดะฝะพ, ััะพ ะดะปั ัะตัะตะฝะธั ััะพะน ะทะฐะดะฐัะธ ะดะพััะฐัะพัะฝะพ ะฟัะพะบัะพัะธัั ะฒัะต ัะธัะปะฐ: x_1, x_1 + 1, ... x_1+m_1-1, x_2, x_2 + 1, .. x_2+m_2 ... x_n, x_n + 1, ... x_n + m_n - 1 ะธ ะพะฟัะตะดะตะปะธัั ัะฒะปัะตััั ะปะธ ัะตะทัะปััะฐั ะฝัะปะตะผ ะธะปะธ ะฝะตั.ย ะงัะพ ะฟัะฐะฒะดะฐ ััะธััะฒะฐั ะธั
ะบะพะปะธัะตััะฒะพ ะฒะฐะผ ะฝะต ัะดะฐัััั ะฒะปะพะถะธััั ะฒ ะขะ. ะะพ-ััะพะผั ะทะฐะผะตัะธะผ ััะพ ะะฐะผ ััะตะฑัะตััั ะฟัะพะบัะพัะธัั ะฝะต ะฟัะพััะพ ะบะฐะบะธะต-ัะพ ัะธัะปะฐ, ะฐ ะฝะตัะบะพะปัะบะพ ะพััะตะทะบะพะฒ ะฒะธะดะฐ [x_i, x_i + m_i - 1]. ะััะบะฐะน f([a,b]) = a^(a+1)^(a+2)..^(b - 1) ^ b.</div><div>ะขะฐะบ ะบะฐะบ f([x_i, x_i + m_i - 1]) = f([1, x_i + m_i - 1]) ^ f([1, x_i ย - 1]);ย ะผะพะถะฝะพ ะบัะพัะธัั ะพััะตะทะพะบ ะทะฐ ะ(1), ััะธััะฒะฐั ัะพ ััะพ f([1,x]) ะผะพะถะฝะพ ััะธัะฐัั ัะฐะบ:</div><div><div>if (x mod 4 == 0) f(x) = x;<br /></div><div>if (x mod 4 == 1) f(x) = 1;</div><div>if (x mod 4 == 2) f(x) = x + 1;</div><div>if (x mod 4 == 3) f(x) = 0;</div><div>ัะพะณะดะฐ ะธะผะตะตะผ ัะปะพะถะฝะพััั ัะตัะตะฝะธั ะ(N)</div></div><div><br /></div><div>D) ย ย ย ย ย ย ย ะ ะตัะฐัั ะตะต ััะพะธะปะพ ัะฐะบ:</div><div>1. ะะตัะตะฑัะฐัั ะฒัะต ะปะตะฒัะต ะฒะตัั
ะฝะธะต ัะณะปั ะฟััะผะพัะณะพะปัะฝะธะบะพะฒ ะณะพะดะฝัั
ะดะปั ัะฐะทะผะตัะตะฝะธั ะณะพัะพะดะฐ ะธ ะดะปั ะบะฐะถะดะพะณะพ ะธะท ะฝะธั
ะฟะพััะธัะฐัั ะบะพะปะธัะตััะฒะพ ะทะตะผะปะธ ะบะพัะพััั ะฑั ะฑัะปะพ ะฝะตะพะฑั
ะพะดะธะผะพ ะฒัะฒะตะทัะธ ะดะปั ัะพะณะพ, ััะพะฑั ะฟะพัััะพะธัั ะณะพัะพะด. ะะปั ััะพะณะพ ะฝะฐะผ ะฝะตะพะฑั
ะพะดะธะผะพ ััะธัะฐัั ััะผะผั ะฝะฐ ะฟััะผะพัะณะพะปัะฝะธะบะต ะธ ะผะธะฝะธะผัะผ. ะะตัะฒะพะต ะดะตะปะฐะตััั ัะฐััะธัะฝัะผะธ ััะผะผะฐะผะธ, ะฐ ะฒัะพัะพะต ะฝะฐ ะฒัะฑะพั ะปะธะฑะพ <a href=\"http://e-maxx.ru/algo/segment_tree\">ะดะฒัะผะตัะฝัะผ ะดะตัะตะฒะพะผ ะพััะตะทะบะพะฒ</a>, ะปะธะฑะพ ะดะปั ััะพะณะพ ะผะพะถะฝะพ ะฟัะธัะฟะพัะพะฑะธัั <a href=\"http://e-maxx.ru/algo/stacks_for_minima\">ะพัะตัะตะดั ั ะผะธะฝะธะผัะผะพะผ ะทะฐ ะ(1) </a>(ะฒะผะตััะพ ะฝะตะต ัะฐะบะถะต ะฟะพะดะพะนะดะตั ัะผัะปััะธั ะตะต ั ะฟะพะผะพััั STL-ะตะฒัะบะธั
ย <a href=\"http://www.cplusplus.com/reference/stl/multiset/\">multiset</a>ย ะธย <a href=\"http://www.cplusplus.com/reference/stl/priority_queue/\">priority_queue</a>).</div><div>2. ะะพัะปะต ะฟะตัะฒะพะณะพ ััะฐะฟะฐ ะฝะตะพะฑั
ะพะดะธะผะพ ัะพะฑัะฐัั ะฒัะต ะดะฐะฝะฝัะต ะฒ ะผะฐััะธะฒ ะฒ ัะพัะผะต (<ะบะพะปะธัะตััะฒะพย ะฒัะฒะตะทะตะฝะฝะพะนย ะทะตะผะปะธ, ย ะบะพะพัะดะธะฝะฐัะฐ ะฒะตัั
ะฝะตะณะพ ัะณะปะฐ>)ย ะธ ะพััะพััะธัะพะฒะฐัั ะตะณะพ ะฒ ะปะตะบัะธะบะพะณัะฐัะธัะตัะบะพะผ ะฟะพััะดะบะต (ะฟะพ ัะฒะตะปะธัะตะฝะธั ะบะพะปะธัะตััะฒะฐ ะทะตะผะปะธ).</div><div>3. ะัะพะนัะธัั ะฟะพ ัะถะตย ะพััะพััะธัะพะฒะฐะฝะฝะพะผัย ะผะฐััะธะฒั ะฟัะพะฒะตััั ะผะพะถะฝะพ ะปะธ ะฟะพััะฐะฒะธัั ะฒ ะดะฐะฝะฝะพะน ะบะปะตัะบะต ะปะตะฒัะน ะฒะตัั
ะฝะธะน ัะณะพะป ะณะพัะพะดะฐ. ะะปั ััะพะณะพ ะฝัะถะฝะพ ะพัะตะฝะธัั ะฝะต ะฝะฐะบะปะฐะดัะฒะฐะตััั ะปะธ ะพะฝ ะฝะฐ ัะถะต ะฟะพััะฐะฒะปะตะฝะฝัะน. ะญัะพ ะผะพะถะฝะพ ะดะตะปะฐัั ะทะฐะฒะตะดั ะผะฐััะธะฒ ะฑัะปะตะฐะฝะพะฒ used[][] ะฒ ะบะพัะพัะพะผ ะฑัะดัั ะพัะผะตัะฐัััั ัะถะต ะฟะพะบััััะต ะบะปะตัะบะธ. ะัะธ ะดะพะฑะฐะฒะปะตะฝะธะธ ะณะพัะพะดะฐ ะฝัะถะฝะพ ะฑัะดะตั ะฟัะพััะพ ะพะฑะฑะตะณะฐัั ะฒะตัั ะฟััะผะพัะณะพะปัะฝะธะบ ะธ ะฟัะพััะฐะฒะปััั ะฒ ะตะณะพ ะบะปะตัะบะฐั
true, ะฐ ะฟัะธ ะทะฐะฟัะพัะต ะฝะฐ ะฒะพะทะผะพะถะฝะพััั ะฟะพะบัััะธั ะฑัะดะตะผ ัะผะพััะตััย <u>ัะพะปัะบะพ</u>ย ะฝะฐ ัะณะปะพะฒัะต ะบะปะตัะบะธ. (ะขะฐะบ "ั
ะฐะปัััะธัั" ะผะพะถะฝะพ ะฟะพัะพะผั ััะพ ั ะฝะฐั ะฒัะต ะฟััะผะพัะณะพะปัะฝะธะบะธ ะพะดะธะฝะฐะบะพะฒะพะณะพ ัะฐะทะผะตัะฐ ะธ ััะฐัะธัะตัะบะพะน ะพัะธะตะฝัะฐัะธะธ). ะะต ัะปะพะถะฝะพ ะฟะพััะธัะฐัั, ััะพ ัะฐะบะธะผ ะพะฑัะฐะทะพะผ ะฑัะดะตั ะฒัะฟะพะปะฝะตะฝะพ ะฒ ััะผะผะต ะฝะต ะฑะพะปะตะต N*M ะพะฟะตัะฐัะธะน.</div><div><br /></div><div>E) ย ย ย ย ย ะะพะถะฝะพ ะฑัะปะพ ะฟะตัะตะนัะธ ะบ ะณัะฐััย <a href=\"https://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D0%BE%D0%B2%D0%B0%D1%80%D1%8C_%D1%82%D0%B5%D1%80%D0%BC%D0%B8%D0%BD%D0%BE%D0%B2_%D1%82%D0%B5%D0%BE%D1%80%D0%B8%D0%B8_%D0%B3%D1%80%D0%B0%D1%84%D0%BE%D0%B2\">ะดะฒะพะนััะฒะตะฝะฝะพะผั</a>ย ะดะฐะฝะฝะพะผั ะธ ะพะฑะฝะฐััะถะธัั, ััะพ ะพะฝ ะดะตัะตะฒะพ, ะฐ ัะฐะบะถะต ัััะฐะฝะพะฒะธัั ะฒะทะฐะธะผะฝะพ ะพะดะฝะพะทะฝะฐัะฝะพะต ัะพะพัะฒะตัััะฒะธะต ะผะตะถะดั ะฟัััะผะธ ะพ ะบะพัะพััั
ัะปะฐ ัะตัั ะฒ ััะปะพะฒะธะธ ะธย ะฝะต ะฟััััะผะธย ะบะพะผะฟะพะฝะตะฝัะฐะผะธ ัะฒัะทะฝะพััะธ ะฒะบะปััะฐััะธั
ะบะพัะตะฝั ะดะฐะฝะฝะพะณะพ ะดะตัะตะฒะฐ. ะขะฐะบะธะต ะบะพะผะฟะพะฝะตะฝัั ะปะตะณะบะพ ััะธัะฐัั ะธัะฟะพะปัะทัั ะะ ะฟะพ ะดะตัะตะฒั:ย DP[u] = (DP[child1] + 1) * (DP[child2] + 1), DP[leaf] = 1. ะะพ ะบะพะฝะตัะฝะพ ัะฐะบะพะต ัะตัะตะฝะธะต ะฝะต ัะบะปะฐะดัะฒะฐะปะพัั ะฒ ะขะ ะธ ะฟะพัะพะผั ะฝัะถะฝะพ ะฑัะปะพ ะธัะฟะพะปัะทัั ััะฐะฒะฝะตะฝะธะต ะะ ัะฒะตััะธ ะบ ะบะพะผะฑะธะฝะฐัะพัะฝะพะน ัะพัะผัะปะต ะฑะปะฐะณะพะดะฐััย ัะตะบัััะตะฝัะฝะพะผัย ัะพะพัะฝะพัะตะฝะธั ะผะตะถะดั "ะฝะธัะฐะผะธ"(ะฟะพะดะดะตัะตะฒัั ะบะพัะพััะต ะธะดัั ะพั ะบัะฐั ะบะฐััั ะฒะณะปัะฑั).ย </div></div>\r\n\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-411-411\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"411\",\n blogEntryId: \"411\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=cf+beta+round+%2315\" class=\"tag notice\" style=\"text-decoration: none;\">cf beta round #15</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+14</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Shtrix\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Shtrix\">\n Shtrix\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/411#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/411#comments\">\n 5\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"421\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (5)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5862\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5862\" href=\"?#comment-5862\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5862\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5862\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Is there an English version of the Contest #15 Report?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5862 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5862 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5862\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5888\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5888\" href=\"?#comment-5888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">unfortunately no:(</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5888\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5889\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/daftcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2095/avatar/5ed186952f4d1cf9.jpg'/> </a>\n <div><a href=\"/profile/daftcoder\" title=\"Expert daftcoder\" class=\"rated-user user-blue\">daftcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:24\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5889\" href=\"?#comment-5889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2095\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, it is: <a href=\"https://daedalusinfinity.blogspot.com/2010/05/codeforces-beta-round-15.html\">link</a>. But there is no solution for E problem.<br />But you can try to use <a href=\"https://translate.google.com/#ru%7Cen\">Google Translate</a>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5889\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5890\" commentParentId=\"5889\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:28\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5890\" href=\"?#comment-5890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5889\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thx</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5890\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5998\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/06/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5998\" href=\"?#comment-5998\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5998\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5998\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I couldn't pass D in Test #7. Could someone give some tips?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5998 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5998 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5998\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-421\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; 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Laser"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Laser</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Petya is the most responsible worker in the Research Institute. So he was asked to make a very important experiment: to melt the chocolate bar with a new laser device. The device consists of a rectangular field of <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span> cells and a robotic arm. Each cell of the field is a <span class=\"tex-span\">1โรโ1</span> square. The robotic arm has two lasers pointed at the field perpendicularly to its surface. At any one time lasers are pointed at the centres of some two cells. Since the lasers are on the robotic hand, their movements are synchronized โ if you move one of the lasers by a vector, another one moves by the same vector.</p><p>The following facts about the experiment are known: </p><ul> <li> initially the whole field is covered with a chocolate bar of the size <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, both lasers are located above the field and are active; </li><li> the chocolate melts within one cell of the field at which the laser is pointed; </li><li> all moves of the robotic arm should be parallel to the sides of the field, after each move the lasers should be pointed at the centres of some two cells; </li><li> at any one time both lasers should be pointed at the field. Petya doesn't want to become a second Gordon Freeman. </li></ul><p>You are given <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> and the cells <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>)</span>, where the lasers are initially pointed at (<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> is a column number, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> is a row number). Rows are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from top to bottom and columns are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. You are to find the amount of cells of the field on which the chocolate can't be melted in the given conditions.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains one integer number <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1โโคโ<i>t</i>โโคโ10000)</span> โ the number of test sets. Each of the following <span class=\"tex-span\"><i>t</i></span> lines describes one test set. Each line contains integer numbers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span>, separated by a space (<span class=\"tex-span\">2โโคโ<i>n</i>,โ<i>m</i>โโคโ10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1โโคโ<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>x</i><sub class=\"lower-index\">2</sub>โโคโ<i>n</i></span>, <span class=\"tex-span\">1โโคโ<i>y</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>โโคโ<i>m</i></span>). Cells <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>)</span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Each of the <span class=\"tex-span\"><i>t</i></span> lines of the output should contain the answer to the corresponding input test set.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>4 4 1 1 3 3<br/>4 3 1 1 2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/>2<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"77bdd7065136ce686a3832574be47195\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b52ce3cbb5b288ae3ade962da7b9abdbaf953f75\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/15\">Codeforces Beta Round 15</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/15/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_83efbff1aa87ecbe09ee90aabaca0df14bd4979c\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Laser</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Petya is the most responsible worker in the Research Institute. So he was asked to make a very important experiment: to melt the chocolate bar with a new laser device. The device consists of a rectangular field of <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span> cells and a robotic arm. Each cell of the field is a <span class=\"tex-span\">1โรโ1</span> square. The robotic arm has two lasers pointed at the field perpendicularly to its surface. At any one time lasers are pointed at the centres of some two cells. Since the lasers are on the robotic hand, their movements are synchronized โ if you move one of the lasers by a vector, another one moves by the same vector.</p><p>The following facts about the experiment are known: </p><ul> <li> initially the whole field is covered with a chocolate bar of the size <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, both lasers are located above the field and are active; </li><li> the chocolate melts within one cell of the field at which the laser is pointed; </li><li> all moves of the robotic arm should be parallel to the sides of the field, after each move the lasers should be pointed at the centres of some two cells; </li><li> at any one time both lasers should be pointed at the field. Petya doesn't want to become a second Gordon Freeman. </li></ul><p>You are given <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> and the cells <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>)</span>, where the lasers are initially pointed at (<span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> is a column number, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\"><i>i</i></sub></span> is a row number). Rows are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>m</i></span> from top to bottom and columns are numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span> from left to right. You are to find the amount of cells of the field on which the chocolate can't be melted in the given conditions.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains one integer number <span class=\"tex-span\"><i>t</i></span> <span class=\"tex-span\">(1โโคโ<i>t</i>โโคโ10000)</span> โ the number of test sets. Each of the following <span class=\"tex-span\"><i>t</i></span> lines describes one test set. Each line contains integer numbers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">1</sub></span>, <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">2</sub></span>, <span class=\"tex-span\"><i>y</i><sub class=\"lower-index\">2</sub></span>, separated by a space (<span class=\"tex-span\">2โโคโ<i>n</i>,โ<i>m</i>โโคโ10<sup class=\"upper-index\">9</sup></span>, <span class=\"tex-span\">1โโคโ<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>x</i><sub class=\"lower-index\">2</sub>โโคโ<i>n</i></span>, <span class=\"tex-span\">1โโคโ<i>y</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>โโคโ<i>m</i></span>). Cells <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>)</span> and <span class=\"tex-span\">(<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>)</span> are distinct.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Each of the <span class=\"tex-span\"><i>t</i></span> lines of the output should contain the answer to the corresponding input test set.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />4 4 1 1 3 3<br />4 3 1 1 2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br />2<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='526752e7c14b5be5b9bfaea946f6b2d1'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" 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title=\"May/29/2010 22:37\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" alt=\"In Russian\" title=\"In Russian\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\">ะ) ย ย ย ย ย ะะตะพะฑั
ะพะดะธะผะพ ะฑัะปะพ ะพััะพััะธัะพะฒะฐัั ะฒัะต ะดะพะผะฐ ะฟะพ ะฒะพะทัะฐััะฐะฝะธั ะบะพะพัะดะธะฝะฐัั ัะตะฝััะฐ ั
. ะะปั ะบะฐะถะดะพะน ะฟะฐัั ะฟะพัะปะตะดะพะฒะฐัะตะปัะฝัั
ะดะพะผะพะฒ (x_i, a_i) ะธ (x_(i+1), a_(i+1)) ะพะฟัะตะดะตะปะธัั ัะฐัััะพัะฝะธะต ะผะตะถะดั ะดะพะผะฐะผะธ:</div><div style=\"text-align: left;\">d = x_(i + 1) - x_i + a_(i+1) / 2 + a_i / 2;</div><div style=\"text-align: left;\">ะตัะปะธ d > T ัะพ ans = ans + 2</div><div style=\"text-align: left;\">ะตัะปะธ d == T ัะพ ans = ans + 1</div><div style=\"text-align: left;\">ะธะฝะฐัะต ะฝะธัะตะณะพ ะฝะต ะดะตะปะฐะตะผ</div><div>ะฒ ะบะพะฝัะต ะบ ะพัะฒะตัั ะฝัะถะฝะพ ะฑัะปะพ ะดะพะฑะฐะฒะธัั ะดะฒะฐ, ััะพะฑั ะตัะต ะทะฐะบัััั ะบัะฐะนะฝะธะต ะฟะพะทะธัะธะธ.</div><div><br /></div><div>B) ย ย ย ย ย ย ะะปั ะฟัะพััะพัั ะฝะฐะฟะธัะฐะฝะธั, ะฝัะถะฝะพ ะฑัะปะพ ะทะฐะผะตัะธัั, ััะพ ะณะตะพะผะตััะธัะตัะบะพะต ะผะตััะพ ัะพัะตะบ ะบะพัะพััะต ะผะพะถะฝะพ ะฒัะถะตัั ะปะฐะทะตัะพะผ ััะพ ะดะฒะฐ ะฟััะผะพัะณะพะปัะฝะธะบะฐ. ะััะฐะฒะฐะปะพัั ัะพะปัะบะพ ะฟะพััะธัะฐัั ะธั
ััะผะผะฐัะฝัั ะฟะปะพัะฐะดั, ััะพ ะดะตะปะฐะตััั ะพัะตะฝั ะฟัะพััะพ ะฟะพ ัะพัะผัะปะต ะฒะบะปััะตะฝะธั-ะธัะบะปััะตะฝะธั. ะ ะฝะต ะทะฐะฑัะดััะต ะฟัะพ 64 ะฑะธัะฝะพะต ัะตะปะพะต!</div><div><br /></div><div>ะก) ย ย ย ย ย ย ะัะต ัะฐะท ะธะทะฒะธะฝัััั ะทะฐ ะพัะธะฑะบั ะฒ ะพะฟะธัะฐะฝะธะธ ะฒั
ะพะดะฐ. ะัะพัะธัะฐะฒ ะฝะตะผะฝะพะณะพ ะผะฐัะตัะธะฐะปะฐ ะฟะพ ัะตะพัะธะธ ะธะณั ะธ ัะธัะปะฐะผ <a href=\"https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D1%8F_%D0%A8%D0%BF%D1%80%D0%B0%D0%B3%D0%B0-%D0%93%D1%80%D0%B0%D0%BD%D0%B4%D0%B8\">ะจะฟัะฐะณะฐ ะัะฐะฝะดะธ</a>ย ะฒะฐะผ ััะฐะฝะตั ะพัะตะฒะธะดะฝะพ, ััะพ ะดะปั ัะตัะตะฝะธั ััะพะน ะทะฐะดะฐัะธ ะดะพััะฐัะพัะฝะพ ะฟัะพะบัะพัะธัั ะฒัะต ัะธัะปะฐ: x_1, x_1 + 1, ... x_1+m_1-1, x_2, x_2 + 1, .. x_2+m_2 ... x_n, x_n + 1, ... x_n + m_n - 1 ะธ ะพะฟัะตะดะตะปะธัั ัะฒะปัะตััั ะปะธ ัะตะทัะปััะฐั ะฝัะปะตะผ ะธะปะธ ะฝะตั.ย ะงัะพ ะฟัะฐะฒะดะฐ ััะธััะฒะฐั ะธั
ะบะพะปะธัะตััะฒะพ ะฒะฐะผ ะฝะต ัะดะฐัััั ะฒะปะพะถะธััั ะฒ ะขะ. ะะพ-ััะพะผั ะทะฐะผะตัะธะผ ััะพ ะะฐะผ ััะตะฑัะตััั ะฟัะพะบัะพัะธัั ะฝะต ะฟัะพััะพ ะบะฐะบะธะต-ัะพ ัะธัะปะฐ, ะฐ ะฝะตัะบะพะปัะบะพ ะพััะตะทะบะพะฒ ะฒะธะดะฐ [x_i, x_i + m_i - 1]. ะััะบะฐะน f([a,b]) = a^(a+1)^(a+2)..^(b - 1) ^ b.</div><div>ะขะฐะบ ะบะฐะบ f([x_i, x_i + m_i - 1]) = f([1, x_i + m_i - 1]) ^ f([1, x_i ย - 1]);ย ะผะพะถะฝะพ ะบัะพัะธัั ะพััะตะทะพะบ ะทะฐ ะ(1), ััะธััะฒะฐั ัะพ ััะพ f([1,x]) ะผะพะถะฝะพ ััะธัะฐัั ัะฐะบ:</div><div><div>if (x mod 4 == 0) f(x) = x;<br /></div><div>if (x mod 4 == 1) f(x) = 1;</div><div>if (x mod 4 == 2) f(x) = x + 1;</div><div>if (x mod 4 == 3) f(x) = 0;</div><div>ัะพะณะดะฐ ะธะผะตะตะผ ัะปะพะถะฝะพััั ัะตัะตะฝะธั ะ(N)</div></div><div><br /></div><div>D) ย ย ย ย ย ย ย ะ ะตัะฐัั ะตะต ััะพะธะปะพ ัะฐะบ:</div><div>1. ะะตัะตะฑัะฐัั ะฒัะต ะปะตะฒัะต ะฒะตัั
ะฝะธะต ัะณะปั ะฟััะผะพัะณะพะปัะฝะธะบะพะฒ ะณะพะดะฝัั
ะดะปั ัะฐะทะผะตัะตะฝะธั ะณะพัะพะดะฐ ะธ ะดะปั ะบะฐะถะดะพะณะพ ะธะท ะฝะธั
ะฟะพััะธัะฐัั ะบะพะปะธัะตััะฒะพ ะทะตะผะปะธ ะบะพัะพััั ะฑั ะฑัะปะพ ะฝะตะพะฑั
ะพะดะธะผะพ ะฒัะฒะตะทัะธ ะดะปั ัะพะณะพ, ััะพะฑั ะฟะพัััะพะธัั ะณะพัะพะด. ะะปั ััะพะณะพ ะฝะฐะผ ะฝะตะพะฑั
ะพะดะธะผะพ ััะธัะฐัั ััะผะผั ะฝะฐ ะฟััะผะพัะณะพะปัะฝะธะบะต ะธ ะผะธะฝะธะผัะผ. ะะตัะฒะพะต ะดะตะปะฐะตััั ัะฐััะธัะฝัะผะธ ััะผะผะฐะผะธ, ะฐ ะฒัะพัะพะต ะฝะฐ ะฒัะฑะพั ะปะธะฑะพ <a href=\"http://e-maxx.ru/algo/segment_tree\">ะดะฒัะผะตัะฝัะผ ะดะตัะตะฒะพะผ ะพััะตะทะบะพะฒ</a>, ะปะธะฑะพ ะดะปั ััะพะณะพ ะผะพะถะฝะพ ะฟัะธัะฟะพัะพะฑะธัั <a href=\"http://e-maxx.ru/algo/stacks_for_minima\">ะพัะตัะตะดั ั ะผะธะฝะธะผัะผะพะผ ะทะฐ ะ(1) </a>(ะฒะผะตััะพ ะฝะตะต ัะฐะบะถะต ะฟะพะดะพะนะดะตั ัะผัะปััะธั ะตะต ั ะฟะพะผะพััั STL-ะตะฒัะบะธั
ย <a href=\"http://www.cplusplus.com/reference/stl/multiset/\">multiset</a>ย ะธย <a href=\"http://www.cplusplus.com/reference/stl/priority_queue/\">priority_queue</a>).</div><div>2. ะะพัะปะต ะฟะตัะฒะพะณะพ ััะฐะฟะฐ ะฝะตะพะฑั
ะพะดะธะผะพ ัะพะฑัะฐัั ะฒัะต ะดะฐะฝะฝัะต ะฒ ะผะฐััะธะฒ ะฒ ัะพัะผะต (<ะบะพะปะธัะตััะฒะพย ะฒัะฒะตะทะตะฝะฝะพะนย ะทะตะผะปะธ, ย ะบะพะพัะดะธะฝะฐัะฐ ะฒะตัั
ะฝะตะณะพ ัะณะปะฐ>)ย ะธ ะพััะพััะธัะพะฒะฐัั ะตะณะพ ะฒ ะปะตะบัะธะบะพะณัะฐัะธัะตัะบะพะผ ะฟะพััะดะบะต (ะฟะพ ัะฒะตะปะธัะตะฝะธั ะบะพะปะธัะตััะฒะฐ ะทะตะผะปะธ).</div><div>3. ะัะพะนัะธัั ะฟะพ ัะถะตย ะพััะพััะธัะพะฒะฐะฝะฝะพะผัย ะผะฐััะธะฒั ะฟัะพะฒะตััั ะผะพะถะฝะพ ะปะธ ะฟะพััะฐะฒะธัั ะฒ ะดะฐะฝะฝะพะน ะบะปะตัะบะต ะปะตะฒัะน ะฒะตัั
ะฝะธะน ัะณะพะป ะณะพัะพะดะฐ. ะะปั ััะพะณะพ ะฝัะถะฝะพ ะพัะตะฝะธัั ะฝะต ะฝะฐะบะปะฐะดัะฒะฐะตััั ะปะธ ะพะฝ ะฝะฐ ัะถะต ะฟะพััะฐะฒะปะตะฝะฝัะน. ะญัะพ ะผะพะถะฝะพ ะดะตะปะฐัั ะทะฐะฒะตะดั ะผะฐััะธะฒ ะฑัะปะตะฐะฝะพะฒ used[][] ะฒ ะบะพัะพัะพะผ ะฑัะดัั ะพัะผะตัะฐัััั ัะถะต ะฟะพะบััััะต ะบะปะตัะบะธ. ะัะธ ะดะพะฑะฐะฒะปะตะฝะธะธ ะณะพัะพะดะฐ ะฝัะถะฝะพ ะฑัะดะตั ะฟัะพััะพ ะพะฑะฑะตะณะฐัั ะฒะตัั ะฟััะผะพัะณะพะปัะฝะธะบ ะธ ะฟัะพััะฐะฒะปััั ะฒ ะตะณะพ ะบะปะตัะบะฐั
true, ะฐ ะฟัะธ ะทะฐะฟัะพัะต ะฝะฐ ะฒะพะทะผะพะถะฝะพััั ะฟะพะบัััะธั ะฑัะดะตะผ ัะผะพััะตััย <u>ัะพะปัะบะพ</u>ย ะฝะฐ ัะณะปะพะฒัะต ะบะปะตัะบะธ. (ะขะฐะบ "ั
ะฐะปัััะธัั" ะผะพะถะฝะพ ะฟะพัะพะผั ััะพ ั ะฝะฐั ะฒัะต ะฟััะผะพัะณะพะปัะฝะธะบะธ ะพะดะธะฝะฐะบะพะฒะพะณะพ ัะฐะทะผะตัะฐ ะธ ััะฐัะธัะตัะบะพะน ะพัะธะตะฝัะฐัะธะธ). ะะต ัะปะพะถะฝะพ ะฟะพััะธัะฐัั, ััะพ ัะฐะบะธะผ ะพะฑัะฐะทะพะผ ะฑัะดะตั ะฒัะฟะพะปะฝะตะฝะพ ะฒ ััะผะผะต ะฝะต ะฑะพะปะตะต N*M ะพะฟะตัะฐัะธะน.</div><div><br /></div><div>E) ย ย ย ย ย ะะพะถะฝะพ ะฑัะปะพ ะฟะตัะตะนัะธ ะบ ะณัะฐััย <a href=\"https://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D0%BE%D0%B2%D0%B0%D1%80%D1%8C_%D1%82%D0%B5%D1%80%D0%BC%D0%B8%D0%BD%D0%BE%D0%B2_%D1%82%D0%B5%D0%BE%D1%80%D0%B8%D0%B8_%D0%B3%D1%80%D0%B0%D1%84%D0%BE%D0%B2\">ะดะฒะพะนััะฒะตะฝะฝะพะผั</a>ย ะดะฐะฝะฝะพะผั ะธ ะพะฑะฝะฐััะถะธัั, ััะพ ะพะฝ ะดะตัะตะฒะพ, ะฐ ัะฐะบะถะต ัััะฐะฝะพะฒะธัั ะฒะทะฐะธะผะฝะพ ะพะดะฝะพะทะฝะฐัะฝะพะต ัะพะพัะฒะตัััะฒะธะต ะผะตะถะดั ะฟัััะผะธ ะพ ะบะพัะพััั
ัะปะฐ ัะตัั ะฒ ััะปะพะฒะธะธ ะธย ะฝะต ะฟััััะผะธย ะบะพะผะฟะพะฝะตะฝัะฐะผะธ ัะฒัะทะฝะพััะธ ะฒะบะปััะฐััะธั
ะบะพัะตะฝั ะดะฐะฝะฝะพะณะพ ะดะตัะตะฒะฐ. ะขะฐะบะธะต ะบะพะผะฟะพะฝะตะฝัั ะปะตะณะบะพ ััะธัะฐัั ะธัะฟะพะปัะทัั ะะ ะฟะพ ะดะตัะตะฒั:ย DP[u] = (DP[child1] + 1) * (DP[child2] + 1), DP[leaf] = 1. ะะพ ะบะพะฝะตัะฝะพ ัะฐะบะพะต ัะตัะตะฝะธะต ะฝะต ัะบะปะฐะดัะฒะฐะปะพัั ะฒ ะขะ ะธ ะฟะพัะพะผั ะฝัะถะฝะพ ะฑัะปะพ ะธัะฟะพะปัะทัั ััะฐะฒะฝะตะฝะธะต ะะ ัะฒะตััะธ ะบ ะบะพะผะฑะธะฝะฐัะพัะฝะพะน ัะพัะผัะปะต ะฑะปะฐะณะพะดะฐััย ัะตะบัััะตะฝัะฝะพะผัย ัะพะพัะฝะพัะตะฝะธั ะผะตะถะดั "ะฝะธัะฐะผะธ"(ะฟะพะดะดะตัะตะฒัั ะบะพัะพััะต ะธะดัั ะพั ะบัะฐั ะบะฐััั ะฒะณะปัะฑั).ย </div></div>\r\n\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-411-411\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"411\",\n blogEntryId: \"411\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=cf+beta+round+%2315\" class=\"tag notice\" style=\"text-decoration: none;\">cf beta round #15</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+14</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Shtrix\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Shtrix\">\n Shtrix\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/411#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/411#comments\">\n 5\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"421\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (5)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5862\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5862\" href=\"?#comment-5862\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5862\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5862\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Is there an English version of the Contest #15 Report?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5862 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5862 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5862\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5888\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5888\" href=\"?#comment-5888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">unfortunately no:(</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5888\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5889\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/daftcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2095/avatar/5ed186952f4d1cf9.jpg'/> </a>\n <div><a href=\"/profile/daftcoder\" title=\"Expert daftcoder\" class=\"rated-user user-blue\">daftcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:24\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5889\" href=\"?#comment-5889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2095\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, it is: <a href=\"https://daedalusinfinity.blogspot.com/2010/05/codeforces-beta-round-15.html\">link</a>. But there is no solution for E problem.<br />But you can try to use <a href=\"https://translate.google.com/#ru%7Cen\">Google Translate</a>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5889\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5890\" commentParentId=\"5889\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:28\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5890\" href=\"?#comment-5890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5889\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thx</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5890\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5998\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/06/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5998\" href=\"?#comment-5998\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5998\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5998\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I couldn't pass D in Test #7. Could someone give some tips?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5998 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5998 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5998\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-421\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; 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Industrial Nim"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Industrial Nim</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are <span class=\"tex-span\"><i>n</i></span> stone quarries in Petrograd.</p><p>Each quarry owns <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>i</i></sub></span> dumpers (<span class=\"tex-span\">1โโคโ<i>i</i>โโคโ<i>n</i></span>). It is known that the first dumper of the <span class=\"tex-span\"><i>i</i></span>-th quarry has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> stones in it, the second dumper has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>โ+โ1</span> stones in it, the third has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>โ+โ2</span>, and the <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>i</i></sub></span>-th dumper (the last for the <span class=\"tex-span\"><i>i</i></span>-th quarry) has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>โ+โ<i>m</i><sub class=\"lower-index\"><i>i</i></sub>โ-โ1</span> stones in it.</p><p>Two oligarchs play a well-known game Nim. Players take turns removing stones from dumpers. On each turn, a player can select any dumper and remove any non-zero amount of stones from it. The player who cannot take a stone loses.</p><p>Your task is to find out which oligarch will win, provided that both of them play optimally. The oligarchs asked you not to reveal their names. So, let's call the one who takes the first stone ยซ<span class=\"tex-font-style-tt\">tolik</span>ยป and the other one ยซ<span class=\"tex-font-style-tt\">bolik</span>ยป.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains one integer number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ the amount of quarries. Then there follow <span class=\"tex-span\"><i>n</i></span> lines, each of them contains two space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>x</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>m</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">16</sup></span>) โ the amount of stones in the first dumper of the <span class=\"tex-span\"><i>i</i></span>-th quarry and the number of dumpers at the <span class=\"tex-span\"><i>i</i></span>-th quarry.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output ยซ<span class=\"tex-font-style-tt\">tolik</span>ยป if the oligarch who takes a stone first wins, and ยซ<span class=\"tex-font-style-tt\">bolik</span>ยป otherwise.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>2 1<br/>3 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>tolik<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>1 1<br/>1 1<br/>1 1<br/>1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>bolik<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"18ab5b36f6e8a9f36faa40d7f92f36ad\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b52ce3cbb5b288ae3ade962da7b9abdbaf953f75\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_bb05bd73c7fcf36d58eb7c64f8ee8a30129c707e\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Industrial Nim</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There are <span class=\"tex-span\"><i>n</i></span> stone quarries in Petrograd.</p><p>Each quarry owns <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>i</i></sub></span> dumpers (<span class=\"tex-span\">1โโคโ<i>i</i>โโคโ<i>n</i></span>). It is known that the first dumper of the <span class=\"tex-span\"><i>i</i></span>-th quarry has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> stones in it, the second dumper has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>โ+โ1</span> stones in it, the third has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>โ+โ2</span>, and the <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>i</i></sub></span>-th dumper (the last for the <span class=\"tex-span\"><i>i</i></span>-th quarry) has <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub>โ+โ<i>m</i><sub class=\"lower-index\"><i>i</i></sub>โ-โ1</span> stones in it.</p><p>Two oligarchs play a well-known game Nim. Players take turns removing stones from dumpers. On each turn, a player can select any dumper and remove any non-zero amount of stones from it. The player who cannot take a stone loses.</p><p>Your task is to find out which oligarch will win, provided that both of them play optimally. The oligarchs asked you not to reveal their names. So, let's call the one who takes the first stone ยซ<span class=\"tex-font-style-tt\">tolik</span>ยป and the other one ยซ<span class=\"tex-font-style-tt\">bolik</span>ยป.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains one integer number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ the amount of quarries. Then there follow <span class=\"tex-span\"><i>n</i></span> lines, each of them contains two space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>m</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>x</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>m</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">16</sup></span>) โ the amount of stones in the first dumper of the <span class=\"tex-span\"><i>i</i></span>-th quarry and the number of dumpers at the <span class=\"tex-span\"><i>i</i></span>-th quarry.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output ยซ<span class=\"tex-font-style-tt\">tolik</span>ยป if the oligarch who takes a stone first wins, and ยซ<span class=\"tex-font-style-tt\">bolik</span>ยป otherwise.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />2 1<br />3 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>tolik<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />1 1<br />1 1<br />1 1<br />1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>bolik<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='526752e7c14b5be5b9bfaea946f6b2d1'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 โ Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" 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href=\"/profile/Shtrix\">Shtrix</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/Shtrix\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/Shtrix\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/Shtrix\">Submissions</a></li>\r\n <li><a\r\n href=\"/contests/with/Shtrix\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/Shtrix\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/Shtrix\" style=\"text-decoration:none;color:black !important;\">Shtrix's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"411\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/411\"> ะะพัะพัะบะธะน ัะฐะทะฑะพั ะทะฐะดะฐั CF #15\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Shtrix\" title=\"Candidate Master Shtrix\" class=\"rated-user user-violet\">Shtrix</a>,\r\n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" alt=\"In Russian\" title=\"In Russian\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\">ะ) ย ย ย ย ย ะะตะพะฑั
ะพะดะธะผะพ ะฑัะปะพ ะพััะพััะธัะพะฒะฐัั ะฒัะต ะดะพะผะฐ ะฟะพ ะฒะพะทัะฐััะฐะฝะธั ะบะพะพัะดะธะฝะฐัั ัะตะฝััะฐ ั
. ะะปั ะบะฐะถะดะพะน ะฟะฐัั ะฟะพัะปะตะดะพะฒะฐัะตะปัะฝัั
ะดะพะผะพะฒ (x_i, a_i) ะธ (x_(i+1), a_(i+1)) ะพะฟัะตะดะตะปะธัั ัะฐัััะพัะฝะธะต ะผะตะถะดั ะดะพะผะฐะผะธ:</div><div style=\"text-align: left;\">d = x_(i + 1) - x_i + a_(i+1) / 2 + a_i / 2;</div><div style=\"text-align: left;\">ะตัะปะธ d > T ัะพ ans = ans + 2</div><div style=\"text-align: left;\">ะตัะปะธ d == T ัะพ ans = ans + 1</div><div style=\"text-align: left;\">ะธะฝะฐัะต ะฝะธัะตะณะพ ะฝะต ะดะตะปะฐะตะผ</div><div>ะฒ ะบะพะฝัะต ะบ ะพัะฒะตัั ะฝัะถะฝะพ ะฑัะปะพ ะดะพะฑะฐะฒะธัั ะดะฒะฐ, ััะพะฑั ะตัะต ะทะฐะบัััั ะบัะฐะนะฝะธะต ะฟะพะทะธัะธะธ.</div><div><br /></div><div>B) ย ย ย ย ย ย ะะปั ะฟัะพััะพัั ะฝะฐะฟะธัะฐะฝะธั, ะฝัะถะฝะพ ะฑัะปะพ ะทะฐะผะตัะธัั, ััะพ ะณะตะพะผะตััะธัะตัะบะพะต ะผะตััะพ ัะพัะตะบ ะบะพัะพััะต ะผะพะถะฝะพ ะฒัะถะตัั ะปะฐะทะตัะพะผ ััะพ ะดะฒะฐ ะฟััะผะพัะณะพะปัะฝะธะบะฐ. ะััะฐะฒะฐะปะพัั ัะพะปัะบะพ ะฟะพััะธัะฐัั ะธั
ััะผะผะฐัะฝัั ะฟะปะพัะฐะดั, ััะพ ะดะตะปะฐะตััั ะพัะตะฝั ะฟัะพััะพ ะฟะพ ัะพัะผัะปะต ะฒะบะปััะตะฝะธั-ะธัะบะปััะตะฝะธั. ะ ะฝะต ะทะฐะฑัะดััะต ะฟัะพ 64 ะฑะธัะฝะพะต ัะตะปะพะต!</div><div><br /></div><div>ะก) ย ย ย ย ย ย ะัะต ัะฐะท ะธะทะฒะธะฝัััั ะทะฐ ะพัะธะฑะบั ะฒ ะพะฟะธัะฐะฝะธะธ ะฒั
ะพะดะฐ. ะัะพัะธัะฐะฒ ะฝะตะผะฝะพะณะพ ะผะฐัะตัะธะฐะปะฐ ะฟะพ ัะตะพัะธะธ ะธะณั ะธ ัะธัะปะฐะผ <a href=\"https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D1%8F_%D0%A8%D0%BF%D1%80%D0%B0%D0%B3%D0%B0-%D0%93%D1%80%D0%B0%D0%BD%D0%B4%D0%B8\">ะจะฟัะฐะณะฐ ะัะฐะฝะดะธ</a>ย ะฒะฐะผ ััะฐะฝะตั ะพัะตะฒะธะดะฝะพ, ััะพ ะดะปั ัะตัะตะฝะธั ััะพะน ะทะฐะดะฐัะธ ะดะพััะฐัะพัะฝะพ ะฟัะพะบัะพัะธัั ะฒัะต ัะธัะปะฐ: x_1, x_1 + 1, ... x_1+m_1-1, x_2, x_2 + 1, .. x_2+m_2 ... x_n, x_n + 1, ... x_n + m_n - 1 ะธ ะพะฟัะตะดะตะปะธัั ัะฒะปัะตััั ะปะธ ัะตะทัะปััะฐั ะฝัะปะตะผ ะธะปะธ ะฝะตั.ย ะงัะพ ะฟัะฐะฒะดะฐ ััะธััะฒะฐั ะธั
ะบะพะปะธัะตััะฒะพ ะฒะฐะผ ะฝะต ัะดะฐัััั ะฒะปะพะถะธััั ะฒ ะขะ. ะะพ-ััะพะผั ะทะฐะผะตัะธะผ ััะพ ะะฐะผ ััะตะฑัะตััั ะฟัะพะบัะพัะธัั ะฝะต ะฟัะพััะพ ะบะฐะบะธะต-ัะพ ัะธัะปะฐ, ะฐ ะฝะตัะบะพะปัะบะพ ะพััะตะทะบะพะฒ ะฒะธะดะฐ [x_i, x_i + m_i - 1]. ะััะบะฐะน f([a,b]) = a^(a+1)^(a+2)..^(b - 1) ^ b.</div><div>ะขะฐะบ ะบะฐะบ f([x_i, x_i + m_i - 1]) = f([1, x_i + m_i - 1]) ^ f([1, x_i ย - 1]);ย ะผะพะถะฝะพ ะบัะพัะธัั ะพััะตะทะพะบ ะทะฐ ะ(1), ััะธััะฒะฐั ัะพ ััะพ f([1,x]) ะผะพะถะฝะพ ััะธัะฐัั ัะฐะบ:</div><div><div>if (x mod 4 == 0) f(x) = x;<br /></div><div>if (x mod 4 == 1) f(x) = 1;</div><div>if (x mod 4 == 2) f(x) = x + 1;</div><div>if (x mod 4 == 3) f(x) = 0;</div><div>ัะพะณะดะฐ ะธะผะตะตะผ ัะปะพะถะฝะพััั ัะตัะตะฝะธั ะ(N)</div></div><div><br /></div><div>D) ย ย ย ย ย ย ย ะ ะตัะฐัั ะตะต ััะพะธะปะพ ัะฐะบ:</div><div>1. ะะตัะตะฑัะฐัั ะฒัะต ะปะตะฒัะต ะฒะตัั
ะฝะธะต ัะณะปั ะฟััะผะพัะณะพะปัะฝะธะบะพะฒ ะณะพะดะฝัั
ะดะปั ัะฐะทะผะตัะตะฝะธั ะณะพัะพะดะฐ ะธ ะดะปั ะบะฐะถะดะพะณะพ ะธะท ะฝะธั
ะฟะพััะธัะฐัั ะบะพะปะธัะตััะฒะพ ะทะตะผะปะธ ะบะพัะพััั ะฑั ะฑัะปะพ ะฝะตะพะฑั
ะพะดะธะผะพ ะฒัะฒะตะทัะธ ะดะปั ัะพะณะพ, ััะพะฑั ะฟะพัััะพะธัั ะณะพัะพะด. ะะปั ััะพะณะพ ะฝะฐะผ ะฝะตะพะฑั
ะพะดะธะผะพ ััะธัะฐัั ััะผะผั ะฝะฐ ะฟััะผะพัะณะพะปัะฝะธะบะต ะธ ะผะธะฝะธะผัะผ. ะะตัะฒะพะต ะดะตะปะฐะตััั ัะฐััะธัะฝัะผะธ ััะผะผะฐะผะธ, ะฐ ะฒัะพัะพะต ะฝะฐ ะฒัะฑะพั ะปะธะฑะพ <a href=\"http://e-maxx.ru/algo/segment_tree\">ะดะฒัะผะตัะฝัะผ ะดะตัะตะฒะพะผ ะพััะตะทะบะพะฒ</a>, ะปะธะฑะพ ะดะปั ััะพะณะพ ะผะพะถะฝะพ ะฟัะธัะฟะพัะพะฑะธัั <a href=\"http://e-maxx.ru/algo/stacks_for_minima\">ะพัะตัะตะดั ั ะผะธะฝะธะผัะผะพะผ ะทะฐ ะ(1) </a>(ะฒะผะตััะพ ะฝะตะต ัะฐะบะถะต ะฟะพะดะพะนะดะตั ัะผัะปััะธั ะตะต ั ะฟะพะผะพััั STL-ะตะฒัะบะธั
ย <a href=\"http://www.cplusplus.com/reference/stl/multiset/\">multiset</a>ย ะธย <a href=\"http://www.cplusplus.com/reference/stl/priority_queue/\">priority_queue</a>).</div><div>2. ะะพัะปะต ะฟะตัะฒะพะณะพ ััะฐะฟะฐ ะฝะตะพะฑั
ะพะดะธะผะพ ัะพะฑัะฐัั ะฒัะต ะดะฐะฝะฝัะต ะฒ ะผะฐััะธะฒ ะฒ ัะพัะผะต (<ะบะพะปะธัะตััะฒะพย ะฒัะฒะตะทะตะฝะฝะพะนย ะทะตะผะปะธ, ย ะบะพะพัะดะธะฝะฐัะฐ ะฒะตัั
ะฝะตะณะพ ัะณะปะฐ>)ย ะธ ะพััะพััะธัะพะฒะฐัั ะตะณะพ ะฒ ะปะตะบัะธะบะพะณัะฐัะธัะตัะบะพะผ ะฟะพััะดะบะต (ะฟะพ ัะฒะตะปะธัะตะฝะธั ะบะพะปะธัะตััะฒะฐ ะทะตะผะปะธ).</div><div>3. ะัะพะนัะธัั ะฟะพ ัะถะตย ะพััะพััะธัะพะฒะฐะฝะฝะพะผัย ะผะฐััะธะฒั ะฟัะพะฒะตััั ะผะพะถะฝะพ ะปะธ ะฟะพััะฐะฒะธัั ะฒ ะดะฐะฝะฝะพะน ะบะปะตัะบะต ะปะตะฒัะน ะฒะตัั
ะฝะธะน ัะณะพะป ะณะพัะพะดะฐ. ะะปั ััะพะณะพ ะฝัะถะฝะพ ะพัะตะฝะธัั ะฝะต ะฝะฐะบะปะฐะดัะฒะฐะตััั ะปะธ ะพะฝ ะฝะฐ ัะถะต ะฟะพััะฐะฒะปะตะฝะฝัะน. ะญัะพ ะผะพะถะฝะพ ะดะตะปะฐัั ะทะฐะฒะตะดั ะผะฐััะธะฒ ะฑัะปะตะฐะฝะพะฒ used[][] ะฒ ะบะพัะพัะพะผ ะฑัะดัั ะพัะผะตัะฐัััั ัะถะต ะฟะพะบััััะต ะบะปะตัะบะธ. ะัะธ ะดะพะฑะฐะฒะปะตะฝะธะธ ะณะพัะพะดะฐ ะฝัะถะฝะพ ะฑัะดะตั ะฟัะพััะพ ะพะฑะฑะตะณะฐัั ะฒะตัั ะฟััะผะพัะณะพะปัะฝะธะบ ะธ ะฟัะพััะฐะฒะปััั ะฒ ะตะณะพ ะบะปะตัะบะฐั
true, ะฐ ะฟัะธ ะทะฐะฟัะพัะต ะฝะฐ ะฒะพะทะผะพะถะฝะพััั ะฟะพะบัััะธั ะฑัะดะตะผ ัะผะพััะตััย <u>ัะพะปัะบะพ</u>ย ะฝะฐ ัะณะปะพะฒัะต ะบะปะตัะบะธ. (ะขะฐะบ "ั
ะฐะปัััะธัั" ะผะพะถะฝะพ ะฟะพัะพะผั ััะพ ั ะฝะฐั ะฒัะต ะฟััะผะพัะณะพะปัะฝะธะบะธ ะพะดะธะฝะฐะบะพะฒะพะณะพ ัะฐะทะผะตัะฐ ะธ ััะฐัะธัะตัะบะพะน ะพัะธะตะฝัะฐัะธะธ). ะะต ัะปะพะถะฝะพ ะฟะพััะธัะฐัั, ััะพ ัะฐะบะธะผ ะพะฑัะฐะทะพะผ ะฑัะดะตั ะฒัะฟะพะปะฝะตะฝะพ ะฒ ััะผะผะต ะฝะต ะฑะพะปะตะต N*M ะพะฟะตัะฐัะธะน.</div><div><br /></div><div>E) ย ย ย ย ย ะะพะถะฝะพ ะฑัะปะพ ะฟะตัะตะนัะธ ะบ ะณัะฐััย <a href=\"https://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D0%BE%D0%B2%D0%B0%D1%80%D1%8C_%D1%82%D0%B5%D1%80%D0%BC%D0%B8%D0%BD%D0%BE%D0%B2_%D1%82%D0%B5%D0%BE%D1%80%D0%B8%D0%B8_%D0%B3%D1%80%D0%B0%D1%84%D0%BE%D0%B2\">ะดะฒะพะนััะฒะตะฝะฝะพะผั</a>ย ะดะฐะฝะฝะพะผั ะธ ะพะฑะฝะฐััะถะธัั, ััะพ ะพะฝ ะดะตัะตะฒะพ, ะฐ ัะฐะบะถะต ัััะฐะฝะพะฒะธัั ะฒะทะฐะธะผะฝะพ ะพะดะฝะพะทะฝะฐัะฝะพะต ัะพะพัะฒะตัััะฒะธะต ะผะตะถะดั ะฟัััะผะธ ะพ ะบะพัะพััั
ัะปะฐ ัะตัั ะฒ ััะปะพะฒะธะธ ะธย ะฝะต ะฟััััะผะธย ะบะพะผะฟะพะฝะตะฝัะฐะผะธ ัะฒัะทะฝะพััะธ ะฒะบะปััะฐััะธั
ะบะพัะตะฝั ะดะฐะฝะฝะพะณะพ ะดะตัะตะฒะฐ. ะขะฐะบะธะต ะบะพะผะฟะพะฝะตะฝัั ะปะตะณะบะพ ััะธัะฐัั ะธัะฟะพะปัะทัั ะะ ะฟะพ ะดะตัะตะฒั:ย DP[u] = (DP[child1] + 1) * (DP[child2] + 1), DP[leaf] = 1. ะะพ ะบะพะฝะตัะฝะพ ัะฐะบะพะต ัะตัะตะฝะธะต ะฝะต ัะบะปะฐะดัะฒะฐะปะพัั ะฒ ะขะ ะธ ะฟะพัะพะผั ะฝัะถะฝะพ ะฑัะปะพ ะธัะฟะพะปัะทัั ััะฐะฒะฝะตะฝะธะต ะะ ัะฒะตััะธ ะบ ะบะพะผะฑะธะฝะฐัะพัะฝะพะน ัะพัะผัะปะต ะฑะปะฐะณะพะดะฐััย ัะตะบัััะตะฝัะฝะพะผัย ัะพะพัะฝะพัะตะฝะธั ะผะตะถะดั "ะฝะธัะฐะผะธ"(ะฟะพะดะดะตัะตะฒัั ะบะพัะพััะต ะธะดัั ะพั ะบัะฐั ะบะฐััั ะฒะณะปัะฑั).ย </div></div>\r\n\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-411-411\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"411\",\n blogEntryId: \"411\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=cf+beta+round+%2315\" class=\"tag notice\" style=\"text-decoration: none;\">cf beta round #15</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+14</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Shtrix\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Shtrix\">\n Shtrix\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/411#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/411#comments\">\n 5\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"421\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (5)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5862\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5862\" href=\"?#comment-5862\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5862\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5862\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Is there an English version of the Contest #15 Report?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5862 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5862 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5862\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5888\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5888\" href=\"?#comment-5888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">unfortunately no:(</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5888\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5889\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/daftcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2095/avatar/5ed186952f4d1cf9.jpg'/> </a>\n <div><a href=\"/profile/daftcoder\" title=\"Expert daftcoder\" class=\"rated-user user-blue\">daftcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:24\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5889\" href=\"?#comment-5889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2095\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, it is: <a href=\"https://daedalusinfinity.blogspot.com/2010/05/codeforces-beta-round-15.html\">link</a>. But there is no solution for E problem.<br />But you can try to use <a href=\"https://translate.google.com/#ru%7Cen\">Google Translate</a>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5889\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5890\" commentParentId=\"5889\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:28\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5890\" href=\"?#comment-5890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5889\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thx</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5890\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5998\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/06/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5998\" href=\"?#comment-5998\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5998\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5998\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I couldn't pass D in Test #7. Could someone give some tips?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5998 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5998 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5998\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-421\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; 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Map"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Map</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There is an area map that is a rectangular matrix <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, each cell of the matrix contains the average height of a corresponding area part. Peter works for a company that has to build several cities within this area, each of the cities will occupy a rectangle <span class=\"tex-span\"><i>a</i>โรโ<i>b</i></span> cells on the map. To start construction works in a particular place Peter needs to remove excess ground from the construction site where a new city will be built. To do so he chooses a cell of the minimum height within this site, and removes excess ground from other cells of the site down to this minimum level. Let's consider that to lower the ground level from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span> to <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> (<span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub>โโคโ<i>h</i><sub class=\"lower-index\">2</sub></span>) they need to remove <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub>โ-โ<i>h</i><sub class=\"lower-index\">1</sub></span> ground units.</p><p>Let's call a site's position optimal, if the amount of the ground removed from this site is minimal compared to other possible positions. Peter constructs cities according to the following algorithm: from all the optimum site's positions he chooses the uppermost one. If this position is not unique, he chooses the leftmost one. Then he builds a city on this site. Peter repeats this process untill he can build at least one more city. For sure, he cannot carry out construction works on the occupied cells. Would you, please, help Peter place cities according to the algorithm? </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains four space-separated integers: map sizes <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> and city sizes <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">1โโคโ<i>a</i>โโคโ<i>n</i>โโคโ1000</span>, <span class=\"tex-span\">1โโคโ<i>b</i>โโคโ<i>m</i>โโคโ1000</span>). Then there follow <span class=\"tex-span\"><i>n</i></span> lines, each contains <span class=\"tex-span\"><i>m</i></span> non-negative space-separated numbers, describing the height matrix. Each number doesn't exceed <span class=\"tex-span\">10<sup class=\"upper-index\">9</sup></span>. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output <span class=\"tex-span\"><i>k</i></span> โ the amount of constructed cities. In each of the following <span class=\"tex-span\"><i>k</i></span> lines output 3 space-separated numbers โ the row number and the column number of the upper-left corner of a subsequent construction site, and the amount of the ground to remove from it. Output the sites in the order of their building up.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2 1 2<br/>1 2<br/>3 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>1 1 1<br/>2 1 2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 4 2 2<br/>1 5 3 4<br/>2 7 6 1<br/>1 1 2 2<br/>2 2 1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>3 1 2<br/>3 3 3<br/>1 2 9<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"34091cdd1d6fbfbd9099264fc89ae72c\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b52ce3cbb5b288ae3ade962da7b9abdbaf953f75\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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<a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Map</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>There is an area map that is a rectangular matrix <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, each cell of the matrix contains the average height of a corresponding area part. Peter works for a company that has to build several cities within this area, each of the cities will occupy a rectangle <span class=\"tex-span\"><i>a</i>โรโ<i>b</i></span> cells on the map. To start construction works in a particular place Peter needs to remove excess ground from the construction site where a new city will be built. To do so he chooses a cell of the minimum height within this site, and removes excess ground from other cells of the site down to this minimum level. Let's consider that to lower the ground level from <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub></span> to <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub></span> (<span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">1</sub>โโคโ<i>h</i><sub class=\"lower-index\">2</sub></span>) they need to remove <span class=\"tex-span\"><i>h</i><sub class=\"lower-index\">2</sub>โ-โ<i>h</i><sub class=\"lower-index\">1</sub></span> ground units.</p><p>Let's call a site's position optimal, if the amount of the ground removed from this site is minimal compared to other possible positions. Peter constructs cities according to the following algorithm: from all the optimum site's positions he chooses the uppermost one. If this position is not unique, he chooses the leftmost one. Then he builds a city on this site. Peter repeats this process untill he can build at least one more city. For sure, he cannot carry out construction works on the occupied cells. Would you, please, help Peter place cities according to the algorithm? </p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains four space-separated integers: map sizes <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span> and city sizes <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span> (<span class=\"tex-span\">1โโคโ<i>a</i>โโคโ<i>n</i>โโคโ1000</span>, <span class=\"tex-span\">1โโคโ<i>b</i>โโคโ<i>m</i>โโคโ1000</span>). Then there follow <span class=\"tex-span\"><i>n</i></span> lines, each contains <span class=\"tex-span\"><i>m</i></span> non-negative space-separated numbers, describing the height matrix. Each number doesn't exceed <span class=\"tex-span\">10<sup class=\"upper-index\">9</sup></span>. </p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output <span class=\"tex-span\"><i>k</i></span> โ the amount of constructed cities. In each of the following <span class=\"tex-span\"><i>k</i></span> lines output 3 space-separated numbers โ the row number and the column number of the upper-left corner of a subsequent construction site, and the amount of the ground to remove from it. Output the sites in the order of their building up.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2 1 2<br />1 2<br />3 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />1 1 1<br />2 1 2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 4 2 2<br />1 5 3 4<br />2 7 6 1<br />1 1 2 2<br />2 2 1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />3 1 2<br />3 3 3<br />1 2 9<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if 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none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='526752e7c14b5be5b9bfaea946f6b2d1'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" 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title=\"May/29/2010 22:37\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" alt=\"In Russian\" title=\"In Russian\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\">ะ) ย ย ย ย ย ะะตะพะฑั
ะพะดะธะผะพ ะฑัะปะพ ะพััะพััะธัะพะฒะฐัั ะฒัะต ะดะพะผะฐ ะฟะพ ะฒะพะทัะฐััะฐะฝะธั ะบะพะพัะดะธะฝะฐัั ัะตะฝััะฐ ั
. ะะปั ะบะฐะถะดะพะน ะฟะฐัั ะฟะพัะปะตะดะพะฒะฐัะตะปัะฝัั
ะดะพะผะพะฒ (x_i, a_i) ะธ (x_(i+1), a_(i+1)) ะพะฟัะตะดะตะปะธัั ัะฐัััะพัะฝะธะต ะผะตะถะดั ะดะพะผะฐะผะธ:</div><div style=\"text-align: left;\">d = x_(i + 1) - x_i + a_(i+1) / 2 + a_i / 2;</div><div style=\"text-align: left;\">ะตัะปะธ d > T ัะพ ans = ans + 2</div><div style=\"text-align: left;\">ะตัะปะธ d == T ัะพ ans = ans + 1</div><div style=\"text-align: left;\">ะธะฝะฐัะต ะฝะธัะตะณะพ ะฝะต ะดะตะปะฐะตะผ</div><div>ะฒ ะบะพะฝัะต ะบ ะพัะฒะตัั ะฝัะถะฝะพ ะฑัะปะพ ะดะพะฑะฐะฒะธัั ะดะฒะฐ, ััะพะฑั ะตัะต ะทะฐะบัััั ะบัะฐะนะฝะธะต ะฟะพะทะธัะธะธ.</div><div><br /></div><div>B) ย ย ย ย ย ย ะะปั ะฟัะพััะพัั ะฝะฐะฟะธัะฐะฝะธั, ะฝัะถะฝะพ ะฑัะปะพ ะทะฐะผะตัะธัั, ััะพ ะณะตะพะผะตััะธัะตัะบะพะต ะผะตััะพ ัะพัะตะบ ะบะพัะพััะต ะผะพะถะฝะพ ะฒัะถะตัั ะปะฐะทะตัะพะผ ััะพ ะดะฒะฐ ะฟััะผะพัะณะพะปัะฝะธะบะฐ. ะััะฐะฒะฐะปะพัั ัะพะปัะบะพ ะฟะพััะธัะฐัั ะธั
ััะผะผะฐัะฝัั ะฟะปะพัะฐะดั, ััะพ ะดะตะปะฐะตััั ะพัะตะฝั ะฟัะพััะพ ะฟะพ ัะพัะผัะปะต ะฒะบะปััะตะฝะธั-ะธัะบะปััะตะฝะธั. ะ ะฝะต ะทะฐะฑัะดััะต ะฟัะพ 64 ะฑะธัะฝะพะต ัะตะปะพะต!</div><div><br /></div><div>ะก) ย ย ย ย ย ย ะัะต ัะฐะท ะธะทะฒะธะฝัััั ะทะฐ ะพัะธะฑะบั ะฒ ะพะฟะธัะฐะฝะธะธ ะฒั
ะพะดะฐ. ะัะพัะธัะฐะฒ ะฝะตะผะฝะพะณะพ ะผะฐัะตัะธะฐะปะฐ ะฟะพ ัะตะพัะธะธ ะธะณั ะธ ัะธัะปะฐะผ <a href=\"https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D1%8F_%D0%A8%D0%BF%D1%80%D0%B0%D0%B3%D0%B0-%D0%93%D1%80%D0%B0%D0%BD%D0%B4%D0%B8\">ะจะฟัะฐะณะฐ ะัะฐะฝะดะธ</a>ย ะฒะฐะผ ััะฐะฝะตั ะพัะตะฒะธะดะฝะพ, ััะพ ะดะปั ัะตัะตะฝะธั ััะพะน ะทะฐะดะฐัะธ ะดะพััะฐัะพัะฝะพ ะฟัะพะบัะพัะธัั ะฒัะต ัะธัะปะฐ: x_1, x_1 + 1, ... x_1+m_1-1, x_2, x_2 + 1, .. x_2+m_2 ... x_n, x_n + 1, ... x_n + m_n - 1 ะธ ะพะฟัะตะดะตะปะธัั ัะฒะปัะตััั ะปะธ ัะตะทัะปััะฐั ะฝัะปะตะผ ะธะปะธ ะฝะตั.ย ะงัะพ ะฟัะฐะฒะดะฐ ััะธััะฒะฐั ะธั
ะบะพะปะธัะตััะฒะพ ะฒะฐะผ ะฝะต ัะดะฐัััั ะฒะปะพะถะธััั ะฒ ะขะ. ะะพ-ััะพะผั ะทะฐะผะตัะธะผ ััะพ ะะฐะผ ััะตะฑัะตััั ะฟัะพะบัะพัะธัั ะฝะต ะฟัะพััะพ ะบะฐะบะธะต-ัะพ ัะธัะปะฐ, ะฐ ะฝะตัะบะพะปัะบะพ ะพััะตะทะบะพะฒ ะฒะธะดะฐ [x_i, x_i + m_i - 1]. ะััะบะฐะน f([a,b]) = a^(a+1)^(a+2)..^(b - 1) ^ b.</div><div>ะขะฐะบ ะบะฐะบ f([x_i, x_i + m_i - 1]) = f([1, x_i + m_i - 1]) ^ f([1, x_i ย - 1]);ย ะผะพะถะฝะพ ะบัะพัะธัั ะพััะตะทะพะบ ะทะฐ ะ(1), ััะธััะฒะฐั ัะพ ััะพ f([1,x]) ะผะพะถะฝะพ ััะธัะฐัั ัะฐะบ:</div><div><div>if (x mod 4 == 0) f(x) = x;<br /></div><div>if (x mod 4 == 1) f(x) = 1;</div><div>if (x mod 4 == 2) f(x) = x + 1;</div><div>if (x mod 4 == 3) f(x) = 0;</div><div>ัะพะณะดะฐ ะธะผะตะตะผ ัะปะพะถะฝะพััั ัะตัะตะฝะธั ะ(N)</div></div><div><br /></div><div>D) ย ย ย ย ย ย ย ะ ะตัะฐัั ะตะต ััะพะธะปะพ ัะฐะบ:</div><div>1. ะะตัะตะฑัะฐัั ะฒัะต ะปะตะฒัะต ะฒะตัั
ะฝะธะต ัะณะปั ะฟััะผะพัะณะพะปัะฝะธะบะพะฒ ะณะพะดะฝัั
ะดะปั ัะฐะทะผะตัะตะฝะธั ะณะพัะพะดะฐ ะธ ะดะปั ะบะฐะถะดะพะณะพ ะธะท ะฝะธั
ะฟะพััะธัะฐัั ะบะพะปะธัะตััะฒะพ ะทะตะผะปะธ ะบะพัะพััั ะฑั ะฑัะปะพ ะฝะตะพะฑั
ะพะดะธะผะพ ะฒัะฒะตะทัะธ ะดะปั ัะพะณะพ, ััะพะฑั ะฟะพัััะพะธัั ะณะพัะพะด. ะะปั ััะพะณะพ ะฝะฐะผ ะฝะตะพะฑั
ะพะดะธะผะพ ััะธัะฐัั ััะผะผั ะฝะฐ ะฟััะผะพัะณะพะปัะฝะธะบะต ะธ ะผะธะฝะธะผัะผ. ะะตัะฒะพะต ะดะตะปะฐะตััั ัะฐััะธัะฝัะผะธ ััะผะผะฐะผะธ, ะฐ ะฒัะพัะพะต ะฝะฐ ะฒัะฑะพั ะปะธะฑะพ <a href=\"http://e-maxx.ru/algo/segment_tree\">ะดะฒัะผะตัะฝัะผ ะดะตัะตะฒะพะผ ะพััะตะทะบะพะฒ</a>, ะปะธะฑะพ ะดะปั ััะพะณะพ ะผะพะถะฝะพ ะฟัะธัะฟะพัะพะฑะธัั <a href=\"http://e-maxx.ru/algo/stacks_for_minima\">ะพัะตัะตะดั ั ะผะธะฝะธะผัะผะพะผ ะทะฐ ะ(1) </a>(ะฒะผะตััะพ ะฝะตะต ัะฐะบะถะต ะฟะพะดะพะนะดะตั ัะผัะปััะธั ะตะต ั ะฟะพะผะพััั STL-ะตะฒัะบะธั
ย <a href=\"http://www.cplusplus.com/reference/stl/multiset/\">multiset</a>ย ะธย <a href=\"http://www.cplusplus.com/reference/stl/priority_queue/\">priority_queue</a>).</div><div>2. ะะพัะปะต ะฟะตัะฒะพะณะพ ััะฐะฟะฐ ะฝะตะพะฑั
ะพะดะธะผะพ ัะพะฑัะฐัั ะฒัะต ะดะฐะฝะฝัะต ะฒ ะผะฐััะธะฒ ะฒ ัะพัะผะต (<ะบะพะปะธัะตััะฒะพย ะฒัะฒะตะทะตะฝะฝะพะนย ะทะตะผะปะธ, ย ะบะพะพัะดะธะฝะฐัะฐ ะฒะตัั
ะฝะตะณะพ ัะณะปะฐ>)ย ะธ ะพััะพััะธัะพะฒะฐัั ะตะณะพ ะฒ ะปะตะบัะธะบะพะณัะฐัะธัะตัะบะพะผ ะฟะพััะดะบะต (ะฟะพ ัะฒะตะปะธัะตะฝะธั ะบะพะปะธัะตััะฒะฐ ะทะตะผะปะธ).</div><div>3. ะัะพะนัะธัั ะฟะพ ัะถะตย ะพััะพััะธัะพะฒะฐะฝะฝะพะผัย ะผะฐััะธะฒั ะฟัะพะฒะตััั ะผะพะถะฝะพ ะปะธ ะฟะพััะฐะฒะธัั ะฒ ะดะฐะฝะฝะพะน ะบะปะตัะบะต ะปะตะฒัะน ะฒะตัั
ะฝะธะน ัะณะพะป ะณะพัะพะดะฐ. ะะปั ััะพะณะพ ะฝัะถะฝะพ ะพัะตะฝะธัั ะฝะต ะฝะฐะบะปะฐะดัะฒะฐะตััั ะปะธ ะพะฝ ะฝะฐ ัะถะต ะฟะพััะฐะฒะปะตะฝะฝัะน. ะญัะพ ะผะพะถะฝะพ ะดะตะปะฐัั ะทะฐะฒะตะดั ะผะฐััะธะฒ ะฑัะปะตะฐะฝะพะฒ used[][] ะฒ ะบะพัะพัะพะผ ะฑัะดัั ะพัะผะตัะฐัััั ัะถะต ะฟะพะบััััะต ะบะปะตัะบะธ. ะัะธ ะดะพะฑะฐะฒะปะตะฝะธะธ ะณะพัะพะดะฐ ะฝัะถะฝะพ ะฑัะดะตั ะฟัะพััะพ ะพะฑะฑะตะณะฐัั ะฒะตัั ะฟััะผะพัะณะพะปัะฝะธะบ ะธ ะฟัะพััะฐะฒะปััั ะฒ ะตะณะพ ะบะปะตัะบะฐั
true, ะฐ ะฟัะธ ะทะฐะฟัะพัะต ะฝะฐ ะฒะพะทะผะพะถะฝะพััั ะฟะพะบัััะธั ะฑัะดะตะผ ัะผะพััะตััย <u>ัะพะปัะบะพ</u>ย ะฝะฐ ัะณะปะพะฒัะต ะบะปะตัะบะธ. (ะขะฐะบ "ั
ะฐะปัััะธัั" ะผะพะถะฝะพ ะฟะพัะพะผั ััะพ ั ะฝะฐั ะฒัะต ะฟััะผะพัะณะพะปัะฝะธะบะธ ะพะดะธะฝะฐะบะพะฒะพะณะพ ัะฐะทะผะตัะฐ ะธ ััะฐัะธัะตัะบะพะน ะพัะธะตะฝัะฐัะธะธ). ะะต ัะปะพะถะฝะพ ะฟะพััะธัะฐัั, ััะพ ัะฐะบะธะผ ะพะฑัะฐะทะพะผ ะฑัะดะตั ะฒัะฟะพะปะฝะตะฝะพ ะฒ ััะผะผะต ะฝะต ะฑะพะปะตะต N*M ะพะฟะตัะฐัะธะน.</div><div><br /></div><div>E) ย ย ย ย ย ะะพะถะฝะพ ะฑัะปะพ ะฟะตัะตะนัะธ ะบ ะณัะฐััย <a href=\"https://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D0%BE%D0%B2%D0%B0%D1%80%D1%8C_%D1%82%D0%B5%D1%80%D0%BC%D0%B8%D0%BD%D0%BE%D0%B2_%D1%82%D0%B5%D0%BE%D1%80%D0%B8%D0%B8_%D0%B3%D1%80%D0%B0%D1%84%D0%BE%D0%B2\">ะดะฒะพะนััะฒะตะฝะฝะพะผั</a>ย ะดะฐะฝะฝะพะผั ะธ ะพะฑะฝะฐััะถะธัั, ััะพ ะพะฝ ะดะตัะตะฒะพ, ะฐ ัะฐะบะถะต ัััะฐะฝะพะฒะธัั ะฒะทะฐะธะผะฝะพ ะพะดะฝะพะทะฝะฐัะฝะพะต ัะพะพัะฒะตัััะฒะธะต ะผะตะถะดั ะฟัััะผะธ ะพ ะบะพัะพััั
ัะปะฐ ัะตัั ะฒ ััะปะพะฒะธะธ ะธย ะฝะต ะฟััััะผะธย ะบะพะผะฟะพะฝะตะฝัะฐะผะธ ัะฒัะทะฝะพััะธ ะฒะบะปััะฐััะธั
ะบะพัะตะฝั ะดะฐะฝะฝะพะณะพ ะดะตัะตะฒะฐ. ะขะฐะบะธะต ะบะพะผะฟะพะฝะตะฝัั ะปะตะณะบะพ ััะธัะฐัั ะธัะฟะพะปัะทัั ะะ ะฟะพ ะดะตัะตะฒั:ย DP[u] = (DP[child1] + 1) * (DP[child2] + 1), DP[leaf] = 1. ะะพ ะบะพะฝะตัะฝะพ ัะฐะบะพะต ัะตัะตะฝะธะต ะฝะต ัะบะปะฐะดัะฒะฐะปะพัั ะฒ ะขะ ะธ ะฟะพัะพะผั ะฝัะถะฝะพ ะฑัะปะพ ะธัะฟะพะปัะทัั ััะฐะฒะฝะตะฝะธะต ะะ ัะฒะตััะธ ะบ ะบะพะผะฑะธะฝะฐัะพัะฝะพะน ัะพัะผัะปะต ะฑะปะฐะณะพะดะฐััย ัะตะบัััะตะฝัะฝะพะผัย ัะพะพัะฝะพัะตะฝะธั ะผะตะถะดั "ะฝะธัะฐะผะธ"(ะฟะพะดะดะตัะตะฒัั ะบะพัะพััะต ะธะดัั ะพั ะบัะฐั ะบะฐััั ะฒะณะปัะฑั).ย </div></div>\r\n\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-411-411\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"411\",\n blogEntryId: \"411\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=cf+beta+round+%2315\" class=\"tag notice\" style=\"text-decoration: none;\">cf beta round #15</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+14</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Shtrix\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Shtrix\">\n Shtrix\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/411#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/411#comments\">\n 5\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"421\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (5)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5862\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5862\" href=\"?#comment-5862\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5862\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5862\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Is there an English version of the Contest #15 Report?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5862 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5862 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5862\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5888\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5888\" href=\"?#comment-5888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">unfortunately no:(</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5888\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5889\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/daftcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2095/avatar/5ed186952f4d1cf9.jpg'/> </a>\n <div><a href=\"/profile/daftcoder\" title=\"Expert daftcoder\" class=\"rated-user user-blue\">daftcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:24\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5889\" href=\"?#comment-5889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2095\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, it is: <a href=\"https://daedalusinfinity.blogspot.com/2010/05/codeforces-beta-round-15.html\">link</a>. But there is no solution for E problem.<br />But you can try to use <a href=\"https://translate.google.com/#ru%7Cen\">Google Translate</a>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5889\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5890\" commentParentId=\"5889\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:28\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5890\" href=\"?#comment-5890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5889\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thx</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5890\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5998\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/06/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5998\" href=\"?#comment-5998\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5998\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5998\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I couldn't pass D in Test #7. Could someone give some tips?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5998 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5998 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5998\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-421\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; 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Triangles"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Triangles</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Last summer Peter was at his granny's in the country, when a wolf attacked sheep in the nearby forest. Now he fears to walk through the forest, to walk round the forest, even to get out of the house. He explains this not by the fear of the wolf, but by a strange, in his opinion, pattern of the forest that has <span class=\"tex-span\"><i>n</i></span> levels, where <span class=\"tex-span\"><i>n</i></span> is an even number.</p><p>In the local council you were given an area map, where the granny's house is marked by point <span class=\"tex-span\"><i>H</i></span>, parts of dense forest are marked grey (see the picture to understand better).</p><p>After a long time at home Peter decided to yield to his granny's persuasions and step out for a breath of fresh air. Being prudent, Peter plans the route beforehand. The route, that Peter considers the most suitable, has the following characteristics: </p><ul> <li> it starts and ends in the same place โ the granny's house; </li><li> the route goes along the forest paths only (these are the segments marked black in the picture); </li><li> the route has positive length (to step out for a breath of fresh air Peter has to cover some distance anyway); </li><li> the route cannot cross itself; </li><li> there shouldn't be any part of dense forest within the part marked out by this route; </li></ul><p>You should find the amount of such suitable oriented routes modulo 1000000009.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/9679343214ebd807266023bbdf5dc0c622c2e808.png\" style=\"max-width: 100.0%;max-height: 100.0%;\"/> </center><p>The example of the area map for <span class=\"tex-span\"><i>n</i>โ=โ12</span> is given in the picture. Since the map has a regular structure, you can construct it for other <span class=\"tex-span\"><i>n</i></span> by analogy using the example.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input data contain the only even integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">6</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only number โ the amount of Peter's routes modulo 1000000009.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>10<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>74<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"f2ee5e06cfb20e1a788aa7e1c2f686f5\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b52ce3cbb5b288ae3ade962da7b9abdbaf953f75\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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}\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_00319e27cc914e2b97a31a8bbab9224e949cb9da\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Triangles</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Last summer Peter was at his granny's in the country, when a wolf attacked sheep in the nearby forest. Now he fears to walk through the forest, to walk round the forest, even to get out of the house. He explains this not by the fear of the wolf, but by a strange, in his opinion, pattern of the forest that has <span class=\"tex-span\"><i>n</i></span> levels, where <span class=\"tex-span\"><i>n</i></span> is an even number.</p><p>In the local council you were given an area map, where the granny's house is marked by point <span class=\"tex-span\"><i>H</i></span>, parts of dense forest are marked grey (see the picture to understand better).</p><p>After a long time at home Peter decided to yield to his granny's persuasions and step out for a breath of fresh air. Being prudent, Peter plans the route beforehand. The route, that Peter considers the most suitable, has the following characteristics: </p><ul> <li> it starts and ends in the same place โ the granny's house; </li><li> the route goes along the forest paths only (these are the segments marked black in the picture); </li><li> the route has positive length (to step out for a breath of fresh air Peter has to cover some distance anyway); </li><li> the route cannot cross itself; </li><li> there shouldn't be any part of dense forest within the part marked out by this route; </li></ul><p>You should find the amount of such suitable oriented routes modulo 1000000009.</p><center> <img class=\"tex-graphics\" src=\"https://espresso.codeforces.com/9679343214ebd807266023bbdf5dc0c622c2e808.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> </center><p>The example of the area map for <span class=\"tex-span\"><i>n</i>โ=โ12</span> is given in the picture. Since the map has a regular structure, you can construct it for other <span class=\"tex-span\"><i>n</i></span> by analogy using the example.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input data contain the only even integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">6</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only number โ the amount of Peter's routes modulo 1000000009.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>10<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>74<br 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:30</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='526752e7c14b5be5b9bfaea946f6b2d1'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"May/29/2010 22:37\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/ru.png\" alt=\"In Russian\" title=\"In Russian\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\">ะ) ย ย ย ย ย ะะตะพะฑั
ะพะดะธะผะพ ะฑัะปะพ ะพััะพััะธัะพะฒะฐัั ะฒัะต ะดะพะผะฐ ะฟะพ ะฒะพะทัะฐััะฐะฝะธั ะบะพะพัะดะธะฝะฐัั ัะตะฝััะฐ ั
. ะะปั ะบะฐะถะดะพะน ะฟะฐัั ะฟะพัะปะตะดะพะฒะฐัะตะปัะฝัั
ะดะพะผะพะฒ (x_i, a_i) ะธ (x_(i+1), a_(i+1)) ะพะฟัะตะดะตะปะธัั ัะฐัััะพัะฝะธะต ะผะตะถะดั ะดะพะผะฐะผะธ:</div><div style=\"text-align: left;\">d = x_(i + 1) - x_i + a_(i+1) / 2 + a_i / 2;</div><div style=\"text-align: left;\">ะตัะปะธ d > T ัะพ ans = ans + 2</div><div style=\"text-align: left;\">ะตัะปะธ d == T ัะพ ans = ans + 1</div><div style=\"text-align: left;\">ะธะฝะฐัะต ะฝะธัะตะณะพ ะฝะต ะดะตะปะฐะตะผ</div><div>ะฒ ะบะพะฝัะต ะบ ะพัะฒะตัั ะฝัะถะฝะพ ะฑัะปะพ ะดะพะฑะฐะฒะธัั ะดะฒะฐ, ััะพะฑั ะตัะต ะทะฐะบัััั ะบัะฐะนะฝะธะต ะฟะพะทะธัะธะธ.</div><div><br /></div><div>B) ย ย ย ย ย ย ะะปั ะฟัะพััะพัั ะฝะฐะฟะธัะฐะฝะธั, ะฝัะถะฝะพ ะฑัะปะพ ะทะฐะผะตัะธัั, ััะพ ะณะตะพะผะตััะธัะตัะบะพะต ะผะตััะพ ัะพัะตะบ ะบะพัะพััะต ะผะพะถะฝะพ ะฒัะถะตัั ะปะฐะทะตัะพะผ ััะพ ะดะฒะฐ ะฟััะผะพัะณะพะปัะฝะธะบะฐ. ะััะฐะฒะฐะปะพัั ัะพะปัะบะพ ะฟะพััะธัะฐัั ะธั
ััะผะผะฐัะฝัั ะฟะปะพัะฐะดั, ััะพ ะดะตะปะฐะตััั ะพัะตะฝั ะฟัะพััะพ ะฟะพ ัะพัะผัะปะต ะฒะบะปััะตะฝะธั-ะธัะบะปััะตะฝะธั. ะ ะฝะต ะทะฐะฑัะดััะต ะฟัะพ 64 ะฑะธัะฝะพะต ัะตะปะพะต!</div><div><br /></div><div>ะก) ย ย ย ย ย ย ะัะต ัะฐะท ะธะทะฒะธะฝัััั ะทะฐ ะพัะธะฑะบั ะฒ ะพะฟะธัะฐะฝะธะธ ะฒั
ะพะดะฐ. ะัะพัะธัะฐะฒ ะฝะตะผะฝะพะณะพ ะผะฐัะตัะธะฐะปะฐ ะฟะพ ัะตะพัะธะธ ะธะณั ะธ ัะธัะปะฐะผ <a href=\"https://ru.wikipedia.org/wiki/%D0%A4%D1%83%D0%BD%D0%BA%D1%86%D0%B8%D1%8F_%D0%A8%D0%BF%D1%80%D0%B0%D0%B3%D0%B0-%D0%93%D1%80%D0%B0%D0%BD%D0%B4%D0%B8\">ะจะฟัะฐะณะฐ ะัะฐะฝะดะธ</a>ย ะฒะฐะผ ััะฐะฝะตั ะพัะตะฒะธะดะฝะพ, ััะพ ะดะปั ัะตัะตะฝะธั ััะพะน ะทะฐะดะฐัะธ ะดะพััะฐัะพัะฝะพ ะฟัะพะบัะพัะธัั ะฒัะต ัะธัะปะฐ: x_1, x_1 + 1, ... x_1+m_1-1, x_2, x_2 + 1, .. x_2+m_2 ... x_n, x_n + 1, ... x_n + m_n - 1 ะธ ะพะฟัะตะดะตะปะธัั ัะฒะปัะตััั ะปะธ ัะตะทัะปััะฐั ะฝัะปะตะผ ะธะปะธ ะฝะตั.ย ะงัะพ ะฟัะฐะฒะดะฐ ััะธััะฒะฐั ะธั
ะบะพะปะธัะตััะฒะพ ะฒะฐะผ ะฝะต ัะดะฐัััั ะฒะปะพะถะธััั ะฒ ะขะ. ะะพ-ััะพะผั ะทะฐะผะตัะธะผ ััะพ ะะฐะผ ััะตะฑัะตััั ะฟัะพะบัะพัะธัั ะฝะต ะฟัะพััะพ ะบะฐะบะธะต-ัะพ ัะธัะปะฐ, ะฐ ะฝะตัะบะพะปัะบะพ ะพััะตะทะบะพะฒ ะฒะธะดะฐ [x_i, x_i + m_i - 1]. ะััะบะฐะน f([a,b]) = a^(a+1)^(a+2)..^(b - 1) ^ b.</div><div>ะขะฐะบ ะบะฐะบ f([x_i, x_i + m_i - 1]) = f([1, x_i + m_i - 1]) ^ f([1, x_i ย - 1]);ย ะผะพะถะฝะพ ะบัะพัะธัั ะพััะตะทะพะบ ะทะฐ ะ(1), ััะธััะฒะฐั ัะพ ััะพ f([1,x]) ะผะพะถะฝะพ ััะธัะฐัั ัะฐะบ:</div><div><div>if (x mod 4 == 0) f(x) = x;<br /></div><div>if (x mod 4 == 1) f(x) = 1;</div><div>if (x mod 4 == 2) f(x) = x + 1;</div><div>if (x mod 4 == 3) f(x) = 0;</div><div>ัะพะณะดะฐ ะธะผะตะตะผ ัะปะพะถะฝะพััั ัะตัะตะฝะธั ะ(N)</div></div><div><br /></div><div>D) ย ย ย ย ย ย ย ะ ะตัะฐัั ะตะต ััะพะธะปะพ ัะฐะบ:</div><div>1. ะะตัะตะฑัะฐัั ะฒัะต ะปะตะฒัะต ะฒะตัั
ะฝะธะต ัะณะปั ะฟััะผะพัะณะพะปัะฝะธะบะพะฒ ะณะพะดะฝัั
ะดะปั ัะฐะทะผะตัะตะฝะธั ะณะพัะพะดะฐ ะธ ะดะปั ะบะฐะถะดะพะณะพ ะธะท ะฝะธั
ะฟะพััะธัะฐัั ะบะพะปะธัะตััะฒะพ ะทะตะผะปะธ ะบะพัะพััั ะฑั ะฑัะปะพ ะฝะตะพะฑั
ะพะดะธะผะพ ะฒัะฒะตะทัะธ ะดะปั ัะพะณะพ, ััะพะฑั ะฟะพัััะพะธัั ะณะพัะพะด. ะะปั ััะพะณะพ ะฝะฐะผ ะฝะตะพะฑั
ะพะดะธะผะพ ััะธัะฐัั ััะผะผั ะฝะฐ ะฟััะผะพัะณะพะปัะฝะธะบะต ะธ ะผะธะฝะธะผัะผ. ะะตัะฒะพะต ะดะตะปะฐะตััั ัะฐััะธัะฝัะผะธ ััะผะผะฐะผะธ, ะฐ ะฒัะพัะพะต ะฝะฐ ะฒัะฑะพั ะปะธะฑะพ <a href=\"http://e-maxx.ru/algo/segment_tree\">ะดะฒัะผะตัะฝัะผ ะดะตัะตะฒะพะผ ะพััะตะทะบะพะฒ</a>, ะปะธะฑะพ ะดะปั ััะพะณะพ ะผะพะถะฝะพ ะฟัะธัะฟะพัะพะฑะธัั <a href=\"http://e-maxx.ru/algo/stacks_for_minima\">ะพัะตัะตะดั ั ะผะธะฝะธะผัะผะพะผ ะทะฐ ะ(1) </a>(ะฒะผะตััะพ ะฝะตะต ัะฐะบะถะต ะฟะพะดะพะนะดะตั ัะผัะปััะธั ะตะต ั ะฟะพะผะพััั STL-ะตะฒัะบะธั
ย <a href=\"http://www.cplusplus.com/reference/stl/multiset/\">multiset</a>ย ะธย <a href=\"http://www.cplusplus.com/reference/stl/priority_queue/\">priority_queue</a>).</div><div>2. ะะพัะปะต ะฟะตัะฒะพะณะพ ััะฐะฟะฐ ะฝะตะพะฑั
ะพะดะธะผะพ ัะพะฑัะฐัั ะฒัะต ะดะฐะฝะฝัะต ะฒ ะผะฐััะธะฒ ะฒ ัะพัะผะต (<ะบะพะปะธัะตััะฒะพย ะฒัะฒะตะทะตะฝะฝะพะนย ะทะตะผะปะธ, ย ะบะพะพัะดะธะฝะฐัะฐ ะฒะตัั
ะฝะตะณะพ ัะณะปะฐ>)ย ะธ ะพััะพััะธัะพะฒะฐัั ะตะณะพ ะฒ ะปะตะบัะธะบะพะณัะฐัะธัะตัะบะพะผ ะฟะพััะดะบะต (ะฟะพ ัะฒะตะปะธัะตะฝะธั ะบะพะปะธัะตััะฒะฐ ะทะตะผะปะธ).</div><div>3. ะัะพะนัะธัั ะฟะพ ัะถะตย ะพััะพััะธัะพะฒะฐะฝะฝะพะผัย ะผะฐััะธะฒั ะฟัะพะฒะตััั ะผะพะถะฝะพ ะปะธ ะฟะพััะฐะฒะธัั ะฒ ะดะฐะฝะฝะพะน ะบะปะตัะบะต ะปะตะฒัะน ะฒะตัั
ะฝะธะน ัะณะพะป ะณะพัะพะดะฐ. ะะปั ััะพะณะพ ะฝัะถะฝะพ ะพัะตะฝะธัั ะฝะต ะฝะฐะบะปะฐะดัะฒะฐะตััั ะปะธ ะพะฝ ะฝะฐ ัะถะต ะฟะพััะฐะฒะปะตะฝะฝัะน. ะญัะพ ะผะพะถะฝะพ ะดะตะปะฐัั ะทะฐะฒะตะดั ะผะฐััะธะฒ ะฑัะปะตะฐะฝะพะฒ used[][] ะฒ ะบะพัะพัะพะผ ะฑัะดัั ะพัะผะตัะฐัััั ัะถะต ะฟะพะบััััะต ะบะปะตัะบะธ. ะัะธ ะดะพะฑะฐะฒะปะตะฝะธะธ ะณะพัะพะดะฐ ะฝัะถะฝะพ ะฑัะดะตั ะฟัะพััะพ ะพะฑะฑะตะณะฐัั ะฒะตัั ะฟััะผะพัะณะพะปัะฝะธะบ ะธ ะฟัะพััะฐะฒะปััั ะฒ ะตะณะพ ะบะปะตัะบะฐั
true, ะฐ ะฟัะธ ะทะฐะฟัะพัะต ะฝะฐ ะฒะพะทะผะพะถะฝะพััั ะฟะพะบัััะธั ะฑัะดะตะผ ัะผะพััะตััย <u>ัะพะปัะบะพ</u>ย ะฝะฐ ัะณะปะพะฒัะต ะบะปะตัะบะธ. (ะขะฐะบ "ั
ะฐะปัััะธัั" ะผะพะถะฝะพ ะฟะพัะพะผั ััะพ ั ะฝะฐั ะฒัะต ะฟััะผะพัะณะพะปัะฝะธะบะธ ะพะดะธะฝะฐะบะพะฒะพะณะพ ัะฐะทะผะตัะฐ ะธ ััะฐัะธัะตัะบะพะน ะพัะธะตะฝัะฐัะธะธ). ะะต ัะปะพะถะฝะพ ะฟะพััะธัะฐัั, ััะพ ัะฐะบะธะผ ะพะฑัะฐะทะพะผ ะฑัะดะตั ะฒัะฟะพะปะฝะตะฝะพ ะฒ ััะผะผะต ะฝะต ะฑะพะปะตะต N*M ะพะฟะตัะฐัะธะน.</div><div><br /></div><div>E) ย ย ย ย ย ะะพะถะฝะพ ะฑัะปะพ ะฟะตัะตะนัะธ ะบ ะณัะฐััย <a href=\"https://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D0%BE%D0%B2%D0%B0%D1%80%D1%8C_%D1%82%D0%B5%D1%80%D0%BC%D0%B8%D0%BD%D0%BE%D0%B2_%D1%82%D0%B5%D0%BE%D1%80%D0%B8%D0%B8_%D0%B3%D1%80%D0%B0%D1%84%D0%BE%D0%B2\">ะดะฒะพะนััะฒะตะฝะฝะพะผั</a>ย ะดะฐะฝะฝะพะผั ะธ ะพะฑะฝะฐััะถะธัั, ััะพ ะพะฝ ะดะตัะตะฒะพ, ะฐ ัะฐะบะถะต ัััะฐะฝะพะฒะธัั ะฒะทะฐะธะผะฝะพ ะพะดะฝะพะทะฝะฐัะฝะพะต ัะพะพัะฒะตัััะฒะธะต ะผะตะถะดั ะฟัััะผะธ ะพ ะบะพัะพััั
ัะปะฐ ัะตัั ะฒ ััะปะพะฒะธะธ ะธย ะฝะต ะฟััััะผะธย ะบะพะผะฟะพะฝะตะฝัะฐะผะธ ัะฒัะทะฝะพััะธ ะฒะบะปััะฐััะธั
ะบะพัะตะฝั ะดะฐะฝะฝะพะณะพ ะดะตัะตะฒะฐ. ะขะฐะบะธะต ะบะพะผะฟะพะฝะตะฝัั ะปะตะณะบะพ ััะธัะฐัั ะธัะฟะพะปัะทัั ะะ ะฟะพ ะดะตัะตะฒั:ย DP[u] = (DP[child1] + 1) * (DP[child2] + 1), DP[leaf] = 1. ะะพ ะบะพะฝะตัะฝะพ ัะฐะบะพะต ัะตัะตะฝะธะต ะฝะต ัะบะปะฐะดัะฒะฐะปะพัั ะฒ ะขะ ะธ ะฟะพัะพะผั ะฝัะถะฝะพ ะฑัะปะพ ะธัะฟะพะปัะทัั ััะฐะฒะฝะตะฝะธะต ะะ ัะฒะตััะธ ะบ ะบะพะผะฑะธะฝะฐัะพัะฝะพะน ัะพัะผัะปะต ะฑะปะฐะณะพะดะฐััย ัะตะบัััะตะฝัะฝะพะผัย ัะพะพัะฝะพัะตะฝะธั ะผะตะถะดั "ะฝะธัะฐะผะธ"(ะฟะพะดะดะตัะตะฒัั ะบะพัะพััะต ะธะดัั ะพั ะบัะฐั ะบะฐััั ะฒะณะปัะฑั).ย </div></div>\r\n\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-411-411\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"411\",\n blogEntryId: \"411\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=cf+beta+round+%2315\" class=\"tag notice\" style=\"text-decoration: none;\">cf beta round #15</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+14</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-411\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Shtrix\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Shtrix\">\n Shtrix\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"May/29/2010 22:37\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/411#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/411#comments\">\n 5\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"421\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (5)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5862\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5862\" href=\"?#comment-5862\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5862\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5862\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Is there an English version of the Contest #15 Report?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5862 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5862 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5862\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5888\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5888\" href=\"?#comment-5888\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5888\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5888\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">unfortunately no:(</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5888 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5888 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5888\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5889\" commentParentId=\"5862\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/daftcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2095/avatar/5ed186952f4d1cf9.jpg'/> </a>\n <div><a href=\"/profile/daftcoder\" title=\"Expert daftcoder\" class=\"rated-user user-blue\">daftcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:24\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5889\" href=\"?#comment-5889\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5862\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5889\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2095\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5889\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, it is: <a href=\"https://daedalusinfinity.blogspot.com/2010/05/codeforces-beta-round-15.html\">link</a>. But there is no solution for E problem.<br />But you can try to use <a href=\"https://translate.google.com/#ru%7Cen\">Google Translate</a>.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5889 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5889 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5889\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5890\" commentParentId=\"5889\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/AVoz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3567/avatar/8dfb41162539c305.jpg'/> </a>\n <div><a href=\"/profile/AVoz\" title=\"Specialist AVoz\" class=\"rated-user user-cyan\">AVoz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/05/2010 19:28\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5890\" href=\"?#comment-5890\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-5889\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5890\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3567\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5890\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thx</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5890 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5890 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5890\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"5998\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/lyrics\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3858/avatar/29787cdba9b12888.jpg'/> </a>\n <div><a href=\"/profile/lyrics\" title=\"Expert lyrics\" class=\"rated-user user-blue\">lyrics</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/06/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-5998\" href=\"?#comment-5998\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"5998\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3858\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-5998\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I couldn't pass D in Test #7. Could someone give some tips?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-5998 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-5998 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-5998\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-421\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; 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Flag"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Flag</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>According to a new ISO standard, a flag of every country should have a chequered field <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, each square should be of one of 10 colours, and the flag should be ยซstripedยป: each horizontal row of the flag should contain squares of the same colour, and the colours of adjacent horizontal rows should be different. Berland's government asked you to find out whether their flag meets the new ISO standard.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>m</i>โโคโ100</span>), <span class=\"tex-span\"><i>n</i></span> โ the amount of rows, <span class=\"tex-span\"><i>m</i></span> โ the amount of columns on the flag of Berland. Then there follows the description of the flag: each of the following <span class=\"tex-span\"><i>n</i></span> lines contain <span class=\"tex-span\"><i>m</i></span> characters. Each character is a digit between <span class=\"tex-font-style-tt\">0</span> and <span class=\"tex-font-style-tt\">9</span>, and stands for the colour of the corresponding square.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-font-style-tt\">YES</span>, if the flag meets the new ISO standard, and <span class=\"tex-font-style-tt\">NO</span> otherwise.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>000<br/>111<br/>222<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>000<br/>000<br/>111<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>000<br/>111<br/>002<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4cf8e0d671882a9013e79446a8ccee53\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"09c09aef8ad5be2498175d65869f04dcf51f7d0b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/16\">Codeforces Beta Round 16 (Div. 2 Only)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='4cf8e0d671882a9013e79446a8ccee53'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/16/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='4cf8e0d671882a9013e79446a8ccee53'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"72\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='4cf8e0d671882a9013e79446a8ccee53'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"72\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/422\" title=\"Codeforces Beta Round #16 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"96:97\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/431\" title=\"Codeforces Beta Round #16 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"706:707\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/16\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/16/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/16/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/16/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/16/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/16/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 1px solid rgb(185, 185, 185);\r\n padding: 3px;\r\n margin: 1px;\r\n line-height: 1.1rem;\r\n text-transform: none;\r\n }\r\n\r\n .input-output-copier:hover {\r\n background-color: #def;\r\n }\r\n\r\n .test-explanation textarea {\r\n width: 100%;\r\n height: 1.5em;\r\n }\r\n\r\n .pending-submission-message {\r\n color: darkorange !important;\r\n }\r\n </style>\r\n <script>\r\n const OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n 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{\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_77e132be8684f6630d92e5470b7021f8dc970180\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Flag</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>According to a new ISO standard, a flag of every country should have a chequered field <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, each square should be of one of 10 colours, and the flag should be ยซstripedยป: each horizontal row of the flag should contain squares of the same colour, and the colours of adjacent horizontal rows should be different. Berland's government asked you to find out whether their flag meets the new ISO standard.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>m</i>โโคโ100</span>), <span class=\"tex-span\"><i>n</i></span> โ the amount of rows, <span class=\"tex-span\"><i>m</i></span> โ the amount of columns on the flag of Berland. Then there follows the description of the flag: each of the following <span class=\"tex-span\"><i>n</i></span> lines contain <span class=\"tex-span\"><i>m</i></span> characters. Each character is a digit between <span class=\"tex-font-style-tt\">0</span> and <span class=\"tex-font-style-tt\">9</span>, and stands for the colour of the corresponding square.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-font-style-tt\">YES</span>, if the flag meets the new ISO standard, and <span class=\"tex-font-style-tt\">NO</span> otherwise.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />000<br />111<br />222<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />000<br />000<br />111<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />000<br />111<br />002<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") 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class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2e03790445a5a5b0be02ccd5f8aaf33e'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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class=\"title\">\r\n <a href=\"/blog/entry/121025\"> <p>Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a>,\r\n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\"logo\" src=\"/predownloaded/e3/33/e333915aebea955b43b4ad17845f6dbf58875a0c.png\" style=\"float: right;height: 100.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></p><p>Sugeng enjing, <strong>Codeforces</strong>! ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ</p><p>COMPFEST 15 is happy to invite you to participate in <a href=\"/contest/1876\" title=\"Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)</a> and <a href=\"/contest/1877\" title=\"Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)</a> on <a class=\"contest-time\" contestid=\"1876\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=8&month=10&year=2023&hour=12&min=5&sec=0&p1=166\"><span class=\"format-time-with-dow\">Oct/08/2023 12:05 (Moscow time)</span></a>. Both rounds will be <strong>rated</strong>. You will be given <strong>2 hours and 30 minutes</strong> to solve <strong>7 problems</strong>.</p><h2><strong>Note the unusual time of the round</strong>.</h2><p>The problems are written by <a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-red\" href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\">Pyqe</a>, and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a>.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-legendary\" href=\"/profile/KAN\" title=\"Legendary Grandmaster KAN\"><span class=\"legendary-user-first-letter\">K</span>AN</a> for helping to host the round;</li> <li><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> and <a class=\"rated-user user-orange\" href=\"/profile/ScarletS\" title=\"Master ScarletS\">ScarletS</a> for the based coordination;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/gansixeneh\" title=\"Candidate Master gansixeneh\">gansixeneh</a> and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a> for helping with the problem preparation;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-blue\" href=\"/profile/CyberSleeper\" title=\"Expert CyberSleeper\">CyberSleeper</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Edbert.H\" title=\"Expert Edbert.H\">Edbert.H</a> for providing alternate solutions in the early stages;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for writing the Russian translations;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Aaeria\" title=\"Master Aaeria\">Aaeria</a>, <a class=\"rated-user user-blue\" href=\"/profile/AMnu\" title=\"Expert AMnu\">AMnu</a>, <a class=\"rated-user user-orange\" href=\"/profile/Berted\" title=\"Master Berted\">Berted</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-cyan\" href=\"/profile/buffering\" title=\"Specialist buffering\">buffering</a>, <a class=\"rated-user user-orange\" href=\"/profile/Drew_\" title=\"Master Drew_\">Drew_</a>, <a class=\"rated-user user-legendary\" href=\"/profile/dorijanlendvaj\" title=\"Legendary Grandmaster dorijanlendvaj\"><span class=\"legendary-user-first-letter\">d</span>orijanlendvaj</a>, <a class=\"rated-user user-orange\" href=\"/profile/eggag32\" title=\"Master eggag32\">eggag32</a>, <a class=\"rated-user user-violet\" href=\"/profile/Elben85\" title=\"Candidate Master Elben85\">Elben85</a>, <a class=\"rated-user user-red\" href=\"/profile/emorgan5289\" title=\"International Grandmaster emorgan5289\">emorgan5289</a>, <a class=\"rated-user user-orange\" href=\"/profile/faustaadp\" title=\"Master faustaadp\">faustaadp</a>, <a class=\"rated-user user-red\" href=\"/profile/ffao\" title=\"International Grandmaster ffao\">ffao</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-legendary\" href=\"/profile/gamegame\" title=\"Legendary Grandmaster gamegame\"><span class=\"legendary-user-first-letter\">g</span>amegame</a>, <a class=\"rated-user user-violet\" href=\"/profile/hocky\" title=\"Candidate Master hocky\">hocky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Insta-x\" title=\"Expert Insta-x\">Insta-x</a>, <a class=\"rated-user user-red\" href=\"/profile/jdurie\" title=\"Grandmaster jdurie\">jdurie</a>, <a class=\"rated-user user-orange\" href=\"/profile/joelgun14\" title=\"Master joelgun14\">joelgun14</a>, <a class=\"rated-user user-violet\" href=\"/profile/KerakTelor\" title=\"Candidate Master KerakTelor\">KerakTelor</a>, <a class=\"rated-user user-blue\" href=\"/profile/Marky\" title=\"Expert Marky\">Marky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Murinh0\" title=\"Expert Murinh0\">Murinh0</a>, <a class=\"rated-user user-red\" href=\"/profile/nvmdava\" title=\"Grandmaster nvmdava\">nvmdava</a>, <a class=\"rated-user user-orange\" href=\"/profile/nyab\" title=\"Master nyab\">nyab</a>, <a class=\"rated-user user-orange\" href=\"/profile/Owmicron\" title=\"Master Owmicron\">Owmicron</a>, <a class=\"rated-user user-red\" href=\"/profile/prvocislo\" title=\"Grandmaster prvocislo\">prvocislo</a>, <a class=\"rated-user user-red\" href=\"/profile/PurpleCrayon\" title=\"International Grandmaster PurpleCrayon\">PurpleCrayon</a>, <a class=\"rated-user user-red\" href=\"/profile/rama_pang\" title=\"Grandmaster rama_pang\">rama_pang</a>, <a class=\"rated-user user-blue\" href=\"/profile/TakeMe\" title=\"Expert TakeMe\">TakeMe</a>, <a class=\"rated-user user-blue\" href=\"/profile/sahil_k\" title=\"Expert sahil_k\">sahil_k</a>, <a class=\"rated-user user-red\" href=\"/profile/user202729_\" title=\"International Grandmaster user202729_\">user202729_</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-green\" href=\"/profile/WHCPP\" title=\"Pupil WHCPP\">WHCPP</a>, and <a class=\"rated-user user-violet\" href=\"/profile/ZeroScar\" title=\"Candidate Master ZeroScar\">ZeroScar</a> for testing the contest and providing us very useful feedback;</li> <li>Universitas Indonesia, all the local committees, administrators, and managers of the whole COMPFEST event;</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Codeforces and Polygon platform!</li> </ul><p>COMPFEST itself is an annual event hosted by Universitas Indonesia. It is the largest student-run IT event in Indonesia and competitive programming contest is one of the competitions hosted.</p><p>We hope you will enjoy and have fun in the contest. Muga-muga beja lan isa entuk biji apik!! ๐ช๐ช๐ฅ๐ฅ</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121025\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1876\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1877\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final 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of complaintReasons) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", complaintReason.id);\n $li.find(\"span\")\n .html(getLocalizedName(complaintReason)\n + \" <i class=\\\"icon-question-sign clickable-title\\\" title=\\\"\"\n + getLocalizedDescription(complaintReason)\n + \"\\\"></i>\")\n .attr(\"title\", getLocalizedDescription(complaintReason));\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n if (complaint && complaint.complaintReasonId === complaintReason.id) {\n $li.find(\"input[name=complaintReasonId]\").attr(\"checked\", \"checked\");\n }\n $li.find(\".clickable-title\").click(function () {\n alert(getLocalizedDescription(complaintReason));\n return false;\n }).css(\"position\", \"relative\").css(\"bottom\", \"1px\").css(\"font-size\", \"12px\");\n }\n\n if (complaint) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", 0);\n $li.find(\"span\").html(\"Delete complaint\");\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n }\n\n $popup.find(\"._ComplaintFrame_submitForm\").submit(function () {\n const complaintReasonId = $popup.find(\"input[name=complaintReasonId]:checked\").val();\n if (complaintReasonId === undefined) {\n alert(\"Please select complaint reason\");\n return false;\n }\n\n $.post(\"/data/complaint\", {\n action: \"newComplaint\",\n targetClass: targetClass,\n targetId: targetId,\n complaintReasonId: complaintReasonId\n }, function (response) {\n if (response.success === \"true\") {\n Codeforces.showMessage(\"Complaint has been created\");\n $.facebox.close();\n }\n }, \"json\");\n\n return false;\n });\n }\n }, \"json\");\n\n return false;\n });\n}); </script>\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Pyqe\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Pyqe\">\n Pyqe\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121025#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121025#comments\">\n 41\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121739\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/121114\"> <p>Codeforces Command Lines (2023-10-06)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\" class=\"rated-user user-blue\">Vladosiya</a>,\r\n <a href=\"/topic/121739/en7\">history</a>,\r\n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>We've compiled a list of command lines that Codeforces uses to compile and run solutions in various languages and compilers.</p><p>It is up-to-date as of today (2023-10-06), and we will make efforts to keep it current in the future, but this is not guaranteed.</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121114\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-73866-121739\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"73866\",\n blogEntryId: \"121114\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compilers\" class=\"tag notice\" style=\"text-decoration: none;\">compilers</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compiler+options\" class=\"tag notice\" style=\"text-decoration: none;\">compiler options</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=languages\" class=\"tag notice\" style=\"text-decoration: none;\">languages</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+235</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n <div style=\"position: relative; float: left; left: -1.5rem; top: 1rem;\">\r\n\n\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Vladosiya\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Vladosiya\">\n Vladosiya\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121114#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121114#comments\">\n 8\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121449\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120824\"> <p>Codeforces Round 901 (Div. 1, Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a>,\r\n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I'm pleased to invite you to <a href=\"/contest/1874\" title=\"Codeforces Round 901 (Div. 1)\">Codeforces Round 901 (Div. 1)</a> and <a href=\"/contest/1875\" title=\"Codeforces Round 901 (Div. 2)\">Codeforces Round 901 (Div. 2)</a>. It starts on <a class=\"contest-time\" contestid=\"1874\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=30&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/30/2023 17:35 (Moscow time)</span></a>. It also means, the National Day of China arrives during the round. Wish you a nice vacation! ๐๐๐</p><p>For both divisions, you will have <strong>3 hours</strong> to solve <strong>7 problems</strong>.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his wonderful coordination.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for Russian translation and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for helping us with Russian clarifications.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\">GeZhiyuan</a> for providing all the problems and "a few" rejected problems.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> and <a class=\"rated-user user-red\" href=\"/profile/SanweiTreap\" title=\"Grandmaster SanweiTreap\">SanweiTreap</a> for helping me prepare the problems.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a>, <a class=\"rated-user user-legendary\" href=\"/profile/wangziji\" title=\"Legendary Grandmaster wangziji\"><span class=\"legendary-user-first-letter\">w</span>angziji</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> and <a class=\"rated-user user-legendary\" href=\"/profile/flowerletter\" title=\"Legendary Grandmaster flowerletter\"><span class=\"legendary-user-first-letter\">f</span>lowerletter</a> for Legendary Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/sjcsjcsjc\" title=\"International Grandmaster sjcsjcsjc\">sjcsjcsjc</a>, <a class=\"rated-user user-red\" href=\"/profile/He_Ren\" title=\"International Grandmaster He_Ren\">He_Ren</a>, <a class=\"rated-user user-red\" href=\"/profile/GaryZ005\" title=\"International Grandmaster GaryZ005\">GaryZ005</a>, <a class=\"rated-user user-red\" href=\"/profile/platelet\" title=\"International Grandmaster platelet\">platelet</a>, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a>, <a class=\"rated-user user-red\" href=\"/profile/thenymphsofdelphi\" title=\"International Grandmaster thenymphsofdelphi\">thenymphsofdelphi</a>, <a class=\"rated-user user-red\" href=\"/profile/DerekFeng\" title=\"International Grandmaster DerekFeng\">DerekFeng</a>, <a class=\"rated-user user-red\" href=\"/profile/Juanzhang\" title=\"International Grandmaster Juanzhang\">Juanzhang</a> and <a class=\"rated-user user-red\" href=\"/profile/ttklwxx\" title=\"International Grandmaster ttklwxx\">ttklwxx</a> for International Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/juju527\" title=\"Grandmaster juju527\">juju527</a>, <a class=\"rated-user user-red\" href=\"/profile/zimpha\" title=\"Grandmaster zimpha\">zimpha</a>, <a class=\"rated-user user-red\" href=\"/profile/765\" title=\"Grandmaster 765\">765</a>, <a class=\"rated-user user-red\" href=\"/profile/xuanquang1999\" title=\"Grandmaster xuanquang1999\">xuanquang1999</a>, <a class=\"rated-user user-red\" href=\"/profile/CrTsIr\" title=\"Grandmaster CrTsIr\">CrTsIr</a> and <a class=\"rated-user user-red\" href=\"/profile/EasonTAO\" title=\"Grandmaster EasonTAO\">EasonTAO</a> for Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/SATSKY\" title=\"Master SATSKY\">SATSKY</a>, <a class=\"rated-user user-orange\" href=\"/profile/lanhf\" title=\"Master lanhf\">lanhf</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hank2019\" title=\"Master Hank2019\">Hank2019</a> and <a class=\"rated-user user-orange\" href=\"/profile/Yakumo_Ran\" title=\"Master Yakumo_Ran\">Yakumo_Ran</a> for Master Testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/DaniraSilla\" title=\"Candidate Master DaniraSilla\">DaniraSilla</a> and <a class=\"rated-user user-violet\" href=\"/profile/kriepiekrollie\" title=\"Candidate Master kriepiekrollie\">kriepiekrollie</a> for Candidate Master Testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/raulandreipop\" title=\"Expert raulandreipop\">raulandreipop</a>, <a class=\"rated-user user-blue\" href=\"/profile/micho\" title=\"Expert micho\">micho</a>, <a class=\"rated-user user-blue\" href=\"/profile/alwyn\" title=\"Expert alwyn\">alwyn</a>, <a class=\"rated-user user-blue\" href=\"/profile/ArgintLaAnu\" title=\"Expert ArgintLaAnu\">ArgintLaAnu</a>, <a class=\"rated-user user-blue\" href=\"/profile/IssamOtoz\" title=\"Expert IssamOtoz\">IssamOtoz</a> and <a class=\"rated-user user-blue\" href=\"/profile/jakao\" title=\"Expert jakao\">jakao</a> for Expert Testing.</p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/CLown1331\" title=\"Pupil CLown1331\">CLown1331</a> for Pupil Testing.</p></li> <li><p>You for participating the round.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</p></li> </ul><p>Especially, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his great contribution to the round, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a> for providing user solutions for all the problems, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> for making the announcement and tutorial more readable.</p><p>Finally and most importantly, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> for helping me with everything patiently all the time. This round can't happen without him.</p><p>The main character of the problems will be Jellyfish, a sweet little girl. ๐๐๐</p><p>Score distribution:</p> <ul> <li><p>Div.1: $$$500$$$ โ $$$1250$$$ โ $$$1500$$$ โ $$$2250$$$ โ $$$3000$$$ โ $$$4000$$$ โ $$$5000$$$</p></li> <li><p>Div.2: $$$500$$$ โ $$$1000$$$ โ $$$1000$$$ โ $$$1250$$$ โ $$$2000$$$ โ $$$2250$$$ โ $$$3000$$$</p></li> </ul><p>Good Luck & Have Fun! ๐ฅ๐ฅ๐ฅ</p><p><strong>UPD1:</strong> <a href=\"https://codeforces.com/blog/entry/120943\">Editorial</a> is out.</p><p><strong>UPD2:</strong> Congratulations to the winners!</p> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\"><span class=\"legendary-user-first-letter\">B</span>enq</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Qingyu\" title=\"International Grandmaster Qingyu\">Qingyu</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/amiya\" title=\"Legendary Grandmaster amiya\"><span class=\"legendary-user-first-letter\">a</span>miya</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/RollingPanda\" title=\"Newbie RollingPanda\">RollingPanda</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/WanYuanShenWanDe\" title=\"Newbie WanYuanShenWanDe\">WanYuanShenWanDe</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-red\" href=\"/profile/H_stove\" title=\"Grandmaster H_stove\">H_stove</a></p><p>B. <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>C. <a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></p><p>D. <a class=\"rated-user user-red\" href=\"/profile/ooOAM\" title=\"Grandmaster ooOAM\">ooOAM</a></p><p>E. <a class=\"rated-user user-orange\" href=\"/profile/Salley-Garden\" title=\"Master Salley-Garden\">Salley-Garden</a></p><p>F. <a class=\"rated-user user-red\" href=\"/profile/i_will_be_less_than_blue\" title=\"Grandmaster i_will_be_less_than_blue\">i_will_be_less_than_blue</a></p><p>G. <a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a> (after the contest)</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-blue\" href=\"/profile/Azaml\" title=\"Expert Azaml\">Azaml</a></p><p>B. <a class=\"rated-user user-blue\" href=\"/profile/Shirotsume\" title=\"Expert Shirotsume\">Shirotsume</a></p><p>C. <a class=\"rated-user user-gray\" href=\"/profile/viveksingh912\" title=\"Newbie viveksingh912\">viveksingh912</a></p><p>D. <a class=\"rated-user user-gray\" href=\"/profile/kaiboy\" title=\"Newbie kaiboy\">kaiboy</a></p><p>E. <a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p><p>F. <a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p><p>G. <a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></div></div></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120824\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1874\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1875\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-238039-121449\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"238039\",\n blogEntryId: \"120824\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+165</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/GeZhiyuan\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/GeZhiyuan\">\n GeZhiyuan\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120824#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120824#comments\">\n 231\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121303\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120678\"> <p>Codeforces Round #900 (Div. 3)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AlphaMale06\" title=\"Specialist AlphaMale06\" class=\"rated-user user-cyan\">AlphaMale06</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p><a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a> and I are glad to invite you to the <a href=\"/contest/1878\" title=\"Codeforces Round 900 (Div. 3)\">Codeforces Round 900 (Div. 3)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1878\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=26&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/26/2023 17:35 (Moscow time)</span></a></p><p>You will be given <strong>7 problems</strong> and <strong>2 hours and 15 minutes</strong> to solve them.</p><p>Note that the <strong>penalty</strong> for the wrong submission in this round is <strong>10 minutes</strong>.</p><p>Also note that there will be a <strong>12 hour open hacking phase</strong> after the round.</p><p><a href=\"https://codeforces.com/blog/entry/59228\">Remember</a>, that only the <em>trusted participants of the third division</em> will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a <em>trusted participant of the third division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them)</li> <li>do not have a point of 1900 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, the round will be rated for you.</strong></p><p>Problems have been created and prepared by <a class=\"rated-user user-blue\" href=\"/profile/AlphaMale06\" title=\"Expert AlphaMale06\">AlphaMale06</a>, <a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>.</p><p>We would also to thank:</p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for the amazing coordination and help with preparing a balanced problemset, and for giving us the opportunity to create a Div. 3 round.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Polygon and Codeforces platforms.</li> <li><a class=\"rated-user user-red\" href=\"/profile/JovanB\" title=\"Grandmaster JovanB\">JovanB</a>, <a class=\"rated-user user-red\" href=\"/profile/abc864197532\" title=\"International Grandmaster abc864197532\">abc864197532</a>, <a class=\"rated-user user-red\" href=\"/profile/sevlll777\" title=\"Grandmaster sevlll777\">sevlll777</a> for red testing</li> <li><a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>, <a class=\"rated-user user-orange\" href=\"/profile/n0sk1ll\" title=\"Master n0sk1ll\">n0sk1ll</a>, <a class=\"rated-user user-orange\" href=\"/profile/allllekssssa\" title=\"Master allllekssssa\">allllekssssa</a>, <a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a>, <a class=\"rated-user user-orange\" href=\"/profile/misorin\" title=\"International Master misorin\">misorin</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hyperbolic\" title=\"International Master Hyperbolic\">Hyperbolic</a> for yellow testing</li> <li><a class=\"rated-user user-violet\" href=\"/profile/DAleksa\" title=\"Candidate Master DAleksa\">DAleksa</a>, <a class=\"rated-user user-violet\" href=\"/profile/ljuba\" title=\"Candidate Master ljuba\">ljuba</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex.kudryashov\" title=\"Candidate Master alex.kudryashov\">alex.kudryashov</a> for purple testing</li> <li><a class=\"rated-user user-blue\" href=\"/profile/MihailoT\" title=\"Expert MihailoT\">MihailoT</a>, <a class=\"rated-user user-blue\" href=\"/profile/SashaT9\" title=\"Expert SashaT9\">SashaT9</a>, <a class=\"rated-user user-blue\" href=\"/profile/ELDRVD\" title=\"Expert ELDRVD\">ELDRVD</a>, <a class=\"rated-user user-blue\" href=\"/profile/Chrisedyong\" title=\"Expert Chrisedyong\">Chrisedyong</a>, <a class=\"rated-user user-blue\" href=\"/profile/tryptophan\" title=\"Expert tryptophan\">tryptophan</a> for blue testing</li> <li><a class=\"rated-user user-cyan\" href=\"/profile/Andrijanikolic73\" title=\"Specialist Andrijanikolic73\">Andrijanikolic73</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Mihajlo18\" title=\"Specialist Mihajlo18\">Mihajlo18</a>, <a class=\"rated-user user-cyan\" href=\"/profile/UrosNedic\" title=\"Specialist UrosNedic\">UrosNedic</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Klaus26\" title=\"Specialist Klaus26\">Klaus26</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Escaquejant\" title=\"Specialist Escaquejant\">Escaquejant</a>, <a class=\"rated-user user-cyan\" href=\"/profile/smax294\" title=\"Specialist smax294\">smax294</a>, <a class=\"rated-user user-cyan\" href=\"/profile/max0n\" title=\"Specialist max0n\">max0n</a> for cyan testing</li> <li><a class=\"rated-user user-gray\" href=\"/profile/Budimmm\" title=\"Newbie Budimmm\">Budimmm</a> for gray testing</li> </ol><p>Also a very special thanks to the most dedicated tester I have ever seen, <a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>.</p><p>I wish you luck, and hope you like the problems and learn from them.</p><p>Update: <a href=\"https://codeforces.com/blog/entry/120813\">Editorial</a> is out.</p><p>Congratulations to the winners:</p><p>Unofficial:</p> <ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/SSerxhs\" title=\"International Grandmaster SSerxhs\">SSerxhs</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/neal\" title=\"Legendary Grandmaster neal\"><span class=\"legendary-user-first-letter\">n</span>eal</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/risujiroh\" title=\"International Grandmaster risujiroh\">risujiroh</a></p></li> </ol><p>Official:</p> <ol> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/hackerjohn\" title=\"Specialist hackerjohn\">hackerjohn</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/wahb\" title=\"Specialist wahb\">wahb</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/kutcoder\" title=\"Specialist kutcoder\">kutcoder</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Sxy_Limit\" title=\"Specialist Sxy_Limit\">Sxy_Limit</a></p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/not_rainboy\" title=\"Pupil not_rainboy\">not_rainboy</a></p></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120678\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1878\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 900 (Div. 3)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-269459-121303\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"269459\",\n blogEntryId: \"120678\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+192</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AlphaMale06\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AlphaMale06\">\n AlphaMale06\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120678#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120678#comments\">\n 347\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121269\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120644\"> <p>Codeforces Round 899 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a>,\r\n <a href=\"/topic/121269/en9\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I am pleased to invite you to participate in <a href=\"/contest/1882\" title=\"Codeforces Round 899 (Div. 2)\">Codeforces Round 899 (Div. 2)</a>, which will be held on <a class=\"contest-time\" contestid=\"1882\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=25&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/25/2023 17:35 (Moscow time)</span></a>.</p><p>All problems were written and prepared by me.</p><p>You will be given <strong>5 problems, and one of them is divided into two subtasks</strong>. You will have <strong>2 hours</strong> to solve them.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-orange\" href=\"/profile/irkstepanov\" title=\"International Master irkstepanov\">irkstepanov</a> for excellent coordination and Russian translation!</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for providing useful feedbacks.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a> for helping me much with one problem of the contest.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/ko_osaga\" title=\"Legendary Grandmaster ko_osaga\"><span class=\"legendary-user-first-letter\">k</span>o_osaga</a> for Nutella testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/leinad2\" title=\"Grandmaster leinad2\">leinad2</a>, <a class=\"rated-user user-red\" href=\"/profile/Numbering\" title=\"Grandmaster Numbering\">Numbering</a>, <a class=\"rated-user user-red\" href=\"/profile/qwerasdfzxcl\" title=\"International Grandmaster qwerasdfzxcl\">qwerasdfzxcl</a>, <a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a>, <a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for Red testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Kaling\" title=\"Master Kaling\">Kaling</a>, <a class=\"rated-user user-orange\" href=\"/profile/Mingyu331\" title=\"Master Mingyu331\">Mingyu331</a>, <a class=\"rated-user user-orange\" href=\"/profile/chaeyihwan\" title=\"International Master chaeyihwan\">chaeyihwan</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kawaii2DIdolOfGSHS\" title=\"International Master Kawaii2DIdolOfGSHS\">Kawaii2DIdolOfGSHS</a>, <a class=\"rated-user user-orange\" href=\"/profile/azberjibiou\" title=\"International Master azberjibiou\">azberjibiou</a>, <a class=\"rated-user user-orange\" href=\"/profile/mjhmjh1104\" title=\"Master mjhmjh1104\">mjhmjh1104</a>, <a class=\"rated-user user-orange\" href=\"/profile/DELTARUNE\" title=\"Master DELTARUNE\">DELTARUNE</a>, <a class=\"rated-user user-orange\" href=\"/profile/wuhudsm\" title=\"Master wuhudsm\">wuhudsm</a>, <a class=\"rated-user user-orange\" href=\"/profile/hypergraph_coloring\" title=\"International Master hypergraph_coloring\">hypergraph_coloring</a> for Orange testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/unordered_map\" title=\"Candidate Master unordered_map\">unordered_map</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex0211\" title=\"Candidate Master alex0211\">alex0211</a>, <a class=\"rated-user user-violet\" href=\"/profile/gs20036\" title=\"Candidate Master gs20036\">gs20036</a>, <a class=\"rated-user user-violet\" href=\"/profile/namolbbaemi\" title=\"Candidate Master namolbbaemi\">namolbbaemi</a>, <a class=\"rated-user user-violet\" href=\"/profile/eeeDA\" title=\"Candidate Master eeeDA\">eeeDA</a>, <a class=\"rated-user user-violet\" href=\"/profile/nlog\" title=\"Candidate Master nlog\">nlog</a> for Purple testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/andyandy\" title=\"Expert andyandy\">andyandy</a>, <a class=\"rated-user user-blue\" href=\"/profile/JaewonOh\" title=\"Expert JaewonOh\">JaewonOh</a>, <a class=\"rated-user user-blue\" href=\"/profile/KongUm\" title=\"Expert KongUm\">KongUm</a>, <a class=\"rated-user user-blue\" href=\"/profile/Coruncanius\" title=\"Expert Coruncanius\">Coruncanius</a>, <a class=\"rated-user user-blue\" href=\"/profile/ez_code\" title=\"Expert ez_code\">ez_code</a>, <a class=\"rated-user user-blue\" href=\"/profile/fs_edge\" title=\"Expert fs_edge\">fs_edge</a>, <a class=\"rated-user user-blue\" href=\"/profile/chromate00\" title=\"Expert chromate00\">chromate00</a> for Blue testing.</p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/Hanlana18\" title=\"Newbie Hanlana18\">Hanlana18</a>, <a class=\"rated-user user-gray\" href=\"/profile/papergundam\" title=\"Newbie papergundam\">papergundam</a>, <a class=\"rated-user user-gray\" href=\"/profile/sjmjys954646\" title=\"Newbie sjmjys954646\">sjmjys954646</a> for Gray testing.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for great Polygon and Codeforces platforms!</p></li> <li><p>And last but not least, <a class=\"rated-user user-legendary\" href=\"https://codeforces.com/profile/\">You</a> for participating in the round!</p></li> </ul><p>Score distribution: $$$500 - 1000 - 1500 - 2000 - (2000 + 2000)$$$</p><p>Good luck and enjoy the round!</p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120792\">Editorial</a> is out. </p><p><strong>UPD2</strong>: Congratulations to the winners!</p><p><strong>Official Contestants</strong></p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Lycorisqwq\" title=\"Expert Lycorisqwq\">Lycorisqwq</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/zepto\" title=\"Unrated, zepto\">zepto</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/vjudge39\" title=\"Unrated, vjudge39\">vjudge39</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/Beelzebub_blue\" title=\"Candidate Master Beelzebub_blue\">Beelzebub_blue</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/_t_W_\" title=\"Candidate Master _t_W_\">_t_W_</a></li> </ol><p><strong>Official + Unofficial Contestants</strong></p> <ol> <li><a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/antontrygubO_o\" title=\"International Grandmaster antontrygubO_o\">antontrygubO_o</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a></li> <li><a class=\"rated-user user-orange\" href=\"/profile/KumaTachiRen\" title=\"Master KumaTachiRen\">KumaTachiRen</a></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120644\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1882\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 899 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-272374-121269\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"272374\",\n blogEntryId: \"120644\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+524</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/windva\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/windva\">\n windva\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120644#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120644#comments\">\n 188\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121316\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120691\"> <p>Educational Codeforces Round 155 [Rated for Div. 2]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a>,\r\n <a href=\"/topic/121316/en5\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p>On <a class=\"contest-time\" contestid=\"1879\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=24&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/24/2023 17:35 (Moscow time)</span></a> <a href=\"/contest/1879\" title=\"Educational Codeforces Round 155 (Rated for Div. 2)\">Educational Codeforces Round 155 (Rated for Div. 2)</a> will start.</p><p>Series of Educational Rounds continue being held as <a href=\"https://harbour.space/\">Harbour.Space University</a> initiative! You can read the details about the cooperation between <a href=\"https://harbour.space/\">Harbour.Space University</a> and Codeforces in the <a href=\"https://mirror.codeforces.com/blog/entry/51208\">blog post</a>.</p><p>This round will be <strong>rated for the participants with rating lower than 2100</strong>. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.</p><p>You will be given <strong>6 or 7 problems</strong> and <strong>2 hours</strong> to solve them.</p><p>The problems were invented and prepared by Adilbek <a class=\"rated-user user-orange\" href=\"/profile/adedalic\" title=\"International Master adedalic\">adedalic</a> Dalabaev, Ivan <a class=\"rated-user user-red\" href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\">BledDest</a> Androsov, Maksim <a class=\"rated-user user-violet\" href=\"/profile/Neon\" title=\"Candidate Master Neon\">Neon</a> Mescheryakov, Roman <a class=\"rated-user user-orange\" href=\"/profile/Roms\" title=\"Master Roms\">Roms</a> Glazov and me. Also, huge thanks to Mike <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> Mirzayanov for great systems Polygon and Codeforces.</p><p>Good luck to all the participants!</p><p>Our friends at Harbour.Space also have a message for you:</p> <center><img alt=\"Harbour.Space\" src=\"/predownloaded/29/a4/29a4884273346021dec6559e9785af37a662cc56.png\" style=\"height: 200.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></center> <center style=\"margin: 1.0em;\"><b>FULLY FUNDED SCHOLARSHIPS for Masters in Data Science and Computer Science </b></center><p><em>Scholarships for Master's students in <a href=\"https://harbour.space/computer-science\">Computer Science</a> and <a href=\"https://harbour.space/data-science\">Data Science</a> are available in <a href=\"https://harbour.space\">Harbour.Space University</a> Barcelona campus!</em> </p><p><strong>Scholarship Summary:</strong></p> <ul> <li><em>Fully funded scholarship (29.900 โฌ/year) to study a Masterโs degree in Data Science or Computer Science for two years</em></li> <li><em>Successful applicants will become part of the Universityโs โTalent poolโ and will be shown to the sponsoring companies. In case the candidate is picked for the Work&Study Program from our industry partner, the student starts an internship with a commitment to study 3 hours/day and work for 4 hour/day</em></li> </ul><p><em>Please note preselected candidates will be requested to pay a non-refundable application fee of 85โฌ to study at Harbour.Space University.</em></p><p><em><strong>Candidateโs commitment:</strong></em></p><p><em>You will complete 15 modules (each three weeks long) in one year. The daily class workload is 3 hours, plus homework to complete in your own time.</em></p><p><em><strong>Candidateโs requirements:</strong></em> </p> <ul> <li><em>Bachelor's degree in the field of Mathematics, Statistics, Data Science, Computer Science or similar</em></li> <li><em>English proficiency</em></li> <li><em>Advanced knowledge and experience in Python, SQL, Spark/Scala, and bash</em></li> <li><em>Experienced use of Big Data technologies: Spark, HDFS, Kafka, etc.</em></li> <li><em>Hands-on experience with Data Science techniques: feature engineering,</em></li> <li><em>Strong ML knowledge</em></li> <li><em>Strong Software Engineering Background</em></li> <li><em>Problem-solving aptitude</em></li> </ul> <center style=\"margin: 2.5em;\"> <a href=\"https://harbour.space/account/apply-process?utm_source=codeforces&utm_medium=partner&utm_campaign=bcn_b2b\" style=\"text-decoration: none;font-size: 14.0px;background-color: rgb(98,91,183);color: white;font-weight: bold;padding: 0.5em 1.0em;\">Apply here โ</a> </center><p><strong>UPD:</strong> <a href=\"https://codeforces.com/blog/entry/120773\">Editorial is out</a> </p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120691\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1879\" class=\"notice\" style=\"text-decoration: none;\">Educational Codeforces Round 155 (Rated for Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-42750-121316\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"42750\",\n blogEntryId: \"120691\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+245</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/awoo\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/awoo\">\n awoo\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120691#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120691#comments\">\n 189\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121227\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120602\"> <p>Codeforces Round 898 (Div. 4)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/mesanu\" title=\"Candidate Master mesanu\" class=\"rated-user user-violet\">mesanu</a>,\r\n <a href=\"/topic/121227/en2\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p><a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and I want to invite you to <a href=\"/contest/1873\" title=\"Codeforces Round 898 (Div. 4)\">Codeforces Round 898 (Div. 4)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1873\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=21&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/21/2023 17:35 (Moscow time)</span></a>.</p><p>The format of the event will be identical to Div. 3 rounds:</p> <ul> <li>5-8 tasks;</li> <li>ICPC rules with a penalty of 10 minutes for an incorrect submission;</li> <li>12-hour phase of open hacks after the end of the round (hacks do not give additional points)</li> <li>after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated</li> <li>by default, only "trusted" participants are shown in the results table (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).</li> </ul><p>We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.</p><p>Only <em>trusted participants of the fourth division</em> will be included in the official standings table. This is a forced measure for combating unsporting behaviour. To qualify as <em>a trusted participant of the fourth division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them),</li> <li>do not have a point of 1400 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), then the round will be rated for you.</strong></p><p>Many thanks to the testers: <a class=\"rated-user user-orange\" href=\"/profile/Gheal\" title=\"Master Gheal\">Gheal</a>, <a class=\"rated-user user-orange\" href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\">Phantom_Performer</a>, <a class=\"rated-user user-orange\" href=\"/profile/KrowSavcik\" title=\"Master KrowSavcik\">KrowSavcik</a>, <a class=\"rated-user user-cyan\" href=\"/profile/haochenkang\" title=\"Specialist haochenkang\">haochenkang</a>, <a class=\"rated-user user-cyan\" href=\"/profile/sandry24\" title=\"Specialist sandry24\">sandry24</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>, <a class=\"rated-user user-violet\" href=\"/profile/NintsiChkhaidze\" title=\"Candidate Master NintsiChkhaidze\">NintsiChkhaidze</a>, <a class=\"rated-user user-orange\" href=\"/profile/erekle\" title=\"International Master erekle\">erekle</a>, <a class=\"rated-user user-red\" href=\"/profile/Dominater069\" title=\"Grandmaster Dominater069\">Dominater069</a>, <a class=\"rated-user user-blue\" href=\"/profile/MADE_IN_HEAVEN\" title=\"Expert MADE_IN_HEAVEN\">MADE_IN_HEAVEN</a>, <a class=\"rated-user user-blue\" href=\"/profile/Qualified\" title=\"Expert Qualified\">Qualified</a>.</p><p>We suggest reading all of the problems and hope you will find them interesting!</p><p><strong>Good Luck!</strong></p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120634\">Editorial is out!</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120602\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1873\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 898 (Div. 4)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-188642-121227\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"188642\",\n blogEntryId: \"120602\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+200</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/mesanu\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/mesanu\">\n mesanu\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120602#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120602#comments\">\n 179\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121083\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120458\"> <p>CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/glebustim\" title=\"Grandmaster glebustim\" class=\"rated-user user-red\">glebustim</a>,\r\n <a href=\"/topic/121083/en8\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3>Hello, Codeforces!</h3><p><a class=\"rated-user user-red\" href=\"/profile/SomethingNew\" title=\"International Grandmaster SomethingNew\">SomethingNew</a> and I are glad to invite you to <a href=\"/contest/1870\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a>, which will take place on <a class=\"contest-time\" contestid=\"1870\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=18&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/18/2023 17:35 (Moscow time)</span></a>. You will have 2 hours 15 minutes to solve 8 problems. The round will be rated for everyone.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-orange\" href=\"/profile/74TrAkToR\" title=\"International Master 74TrAkToR\">74TrAkToR</a> for coordinating this round.</li> <li><a class=\"rated-user user-legendary\" href=\"/profile/isaf27\" title=\"Legendary Grandmaster isaf27\"><span class=\"legendary-user-first-letter\">i</span>saf27</a>, <a class=\"rated-user user-legendary\" href=\"/profile/ugly2333\" title=\"Legendary Grandmaster ugly2333\"><span class=\"legendary-user-first-letter\">u</span>gly2333</a>, <a class=\"rated-user user-red\" href=\"/profile/DataStructures\" title=\"Grandmaster DataStructures\">DataStructures</a>, <a class=\"rated-user user-red\" href=\"/profile/Little09\" title=\"International Grandmaster Little09\">Little09</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kieray\" title=\"Master Kieray\">Kieray</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-orange\" href=\"/profile/Dart-Xeyter\" title=\"International Master Dart-Xeyter\">Dart-Xeyter</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/meowcneil\" title=\"Master meowcneil\">meowcneil</a>, <a class=\"rated-user user-orange\" href=\"/profile/127.0.0.1\" title=\"Master 127.0.0.1\">127.0.0.1</a>, <a class=\"rated-user user-violet\" href=\"/profile/Nanani\" title=\"Candidate Master Nanani\">Nanani</a>, <a class=\"rated-user user-violet\" href=\"/profile/nnv-nick\" title=\"Candidate Master nnv-nick\">nnv-nick</a>, <a class=\"rated-user user-violet\" href=\"/profile/SomethingDifferent\" title=\"Candidate Master SomethingDifferent\">SomethingDifferent</a>, <a class=\"rated-user user-blue\" href=\"/profile/vl342\" title=\"Expert vl342\">vl342</a>, <a class=\"rated-user user-blue\" href=\"/profile/shiv_codegen\" title=\"Expert shiv_codegen\">shiv_codegen</a>, <a class=\"rated-user user-cyan\" href=\"/profile/M1lkas\" title=\"Specialist M1lkas\">M1lkas</a>, <a class=\"rated-user user-green\" href=\"/profile/allmath\" title=\"Pupil allmath\">allmath</a>, <a class=\"rated-user user-gray\" href=\"/profile/sdyakonov\" title=\"Newbie sdyakonov\">sdyakonov</a> for testing the round and providing useful feedback.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</li> </ul><h4><strong>Score distribution:</strong></h4><p>500 โ 750 โ 1500 โ 1750 โ 2750 โ 3250 โ 3250 โ 4000</p><p>We hope that our problems will be interesting for you!</p><h4><a href=\"https://codeforces.com/blog/entry/120524\">Editorial</a></h4><p><strong>Congratulations to the winners!</strong></p> <ol> <li><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/emptyhope\" title=\"Legendary Grandmaster emptyhope\"><span class=\"legendary-user-first-letter\">e</span>mptyhope</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/maspy\" title=\"International Grandmaster maspy\">maspy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/AoLiGei\" title=\"Legendary Grandmaster AoLiGei\"><span class=\"legendary-user-first-letter\">A</span>oLiGei</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/noimi\" title=\"Legendary Grandmaster noimi\"><span class=\"legendary-user-first-letter\">n</span>oimi</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></li> </ol><p>And here is the information from our title sponsor:</p><p><img src=\"/predownloaded/ce/9f/ce9f87d5c429f47e7691bef3a8934ebf36af3f15.jpg\" style=\"width: 250.0px;float: right;margin: 0 1.0em 1.0em 1.0em;max-width: 100.0%;max-height: 100.0%;\" /></p><p><em>Hello, Codeforces!</em></p><p><em>We, the <a href=\"https://ton.org/\">TON Foundation</a> team, are pleased to support CodeTON Round 6.</em></p><p><em>The Open Network (TON) is a fully decentralized layer-1 blockchain designed to onboard billions of users to Web3.</em></p><p><em>Since July 2022, <a href=\"/blog/entry/104544\">we have been supporting</a> Codeforces as a title sponsor. This round is another way for us to contribute to the development of the community.</em></p><p><em>The winners of CodeTON Round 6 will receive valuable prizes.</em></p><p><em>The first 1,023 participants will receive prizes in TON cryptocurrency:</em></p> <ul> <li><em>1st place: 1,024 TON</em></li> <li><em>2โ3 places: 512 TON each</em></li> <li><em>4โ7 places: 256 TON each</em></li> <li><em>8โ15 places: 128 TON each</em></li> <li><em>โฆ</em></li> <li><em>512โ1,023 places: 2 TON each</em></li> </ul><p><em>We wish you good luck at CodeTON Round 6 and hope you enjoy the contest!</em></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120458\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1870\" class=\"notice\" style=\"text-decoration: none;\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-223600-121083\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"223600\",\n blogEntryId: \"120458\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+394</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/glebustim\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/glebustim\">\n glebustim\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120458#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120458#comments\">\n 171\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"120865\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120240\"> <p>Codeforces Round #897 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/salyg1n\" title=\"Master salyg1n\" class=\"rated-user user-orange\">salyg1n</a>,\r\n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces! ๐คฏ</p><p><a class=\"rated-user user-red\" href=\"/profile/green_gold_dog\" title=\"Grandmaster green_gold_dog\">green_gold_dog</a>, <a class=\"rated-user user-orange\" href=\"/profile/ace5\" title=\"International Master ace5\">ace5</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> and I <a class=\"rated-user user-orange\" href=\"/profile/salyg1n\" title=\"Master salyg1n\">salyg1n</a> are pleased to invite you to participate in <a href=\"https://codeforces.com/contest/1867\">Codeforces Round 897 (Div. 2)</a>, which will take place on <a href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=11&month=9&year=2023&hour=17&min=35&sec=0&p1=166\">Monday, September 11, 2023 in 17:35</a>.</p><p>This round will be <strong>rated</strong> for participants whose <strong>rating is below 2100</strong>.</p><p>You will be given 6 tasks and 2 hours to solve them. We recommend reading all the tasks. <strong>Interactive tasks may occur in the round</strong>, so we suggest reading this <a href=\"https://codeforces.com/blog/entry/45307\">post</a>.</p><p>We want to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/Aleks5d\" title=\"Grandmaster Aleks5d\">Aleks5d</a> for coordinating the round and improving one of the tasks. ๐ค</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Allvik06\" title=\"International Grandmaster Allvik06\">Allvik06</a>, <a class=\"rated-user user-red\" href=\"/profile/Nutella3000\" title=\"Grandmaster Nutella3000\">Nutella3000</a>, <a class=\"rated-user user-red\" href=\"/profile/arbuzick\" title=\"International Grandmaster arbuzick\">arbuzick</a>, <a class=\"rated-user user-red\" href=\"/profile/alegsandyr\" title=\"Grandmaster alegsandyr\">alegsandyr</a>, <a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/FairyWinx\" title=\"Grandmaster FairyWinx\">FairyWinx</a>, <a class=\"rated-user user-red\" href=\"/profile/zwezdinv\" title=\"Grandmaster zwezdinv\">zwezdinv</a>, <a class=\"rated-user user-orange\" href=\"/profile/valerikk\" title=\"Master valerikk\">valerikk</a>, <a class=\"rated-user user-orange\" href=\"/profile/danya111\" title=\"Master danya111\">danya111</a>, <a class=\"rated-user user-orange\" href=\"/profile/EJIC_B_KEDAX\" title=\"Master EJIC_B_KEDAX\">EJIC_B_KEDAX</a>, <a class=\"rated-user user-orange\" href=\"/profile/dushenkov\" title=\"Master dushenkov\">dushenkov</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/aleksandro\" title=\"Master aleksandro\">aleksandro</a>, <a class=\"rated-user user-orange\" href=\"/profile/Yar_sem\" title=\"Master Yar_sem\">Yar_sem</a>, <a class=\"rated-user user-orange\" href=\"/profile/asafiul\" title=\"Master asafiul\">asafiul</a>, <a class=\"rated-user user-violet\" href=\"/profile/Ivan_len\" title=\"Candidate Master Ivan_len\">Ivan_len</a>, <a class=\"rated-user user-violet\" href=\"/profile/ArtAlex\" title=\"Candidate Master ArtAlex\">ArtAlex</a>, <a class=\"rated-user user-violet\" href=\"/profile/Undying\" title=\"Candidate Master Undying\">Undying</a>, <a class=\"rated-user user-violet\" href=\"/profile/JustNik77\" title=\"Candidate Master JustNik77\">JustNik77</a>, <a class=\"rated-user user-violet\" href=\"/profile/Pavarishko\" title=\"Candidate Master Pavarishko\">Pavarishko</a> and <a class=\"rated-user user-violet\" href=\"/profile/xnor\" title=\"Candidate Master xnor\">xnor</a> for testing the round and giving valuable feedback. ๐ <span style=\"color: rgb(255,255,255);\">orz</span></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/ryskmax\" title=\"Expert ryskmax\">ryskmax</a> for being the only blue tester and giving valuable feedback. ๐ณ </p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/DimaTomsk\" title=\"Master DimaTomsk\">DimaTomsk</a> and <a class=\"rated-user user-orange\" href=\"/profile/ilyakrasnovv\" title=\"Master ilyakrasnovv\">ilyakrasnovv</a> for viewing some of the tasks and giving valuable feedback. ๐ค <span style=\"color: rgb(255,255,255);\"></span></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/stepanov.aa\" title=\"Grandmaster stepanov.aa\">stepanov.aa</a> for <strong>not</strong> testing the round. ๐ฆฅ <span style=\"color: rgb(255,255,255);\">:(</span></p></li> <li><p>The authors of the task <em>5. Overtaking</em> from IOI 2023 for <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> taking a <strong>gold medal</strong>. ๐ฅ <span style=\"color: rgb(255,255,255);\">Too dead? Yes, so am I.</span></p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and <a class=\"rated-user user-admin\" href=\"/profile/geranazavr555\" title=\"Headquarters, geranazavr555\">geranazavr555</a> for the excellent codeforces and polygon platforms. ๐ฆ <span style=\"color: rgb(255,255,255);\">Thank you!</span></p></li> </ul><p>We hope you'll enjoy our problems! Good luck!</p><p><strong>UPD.</strong> Score distribution: $$$500 - 1000 - 1250 - 2000 - (2000 + 1000) - 4000$$$.</p><p><strong>UPD2.</strong> Congratulations to the winners!</p><p><strong>Div. 2</strong></p> <ol> <li><p><a class=\"rated-user user-violet\" href=\"/profile/candidatecandidatemaster\" title=\"Candidate Master candidatecandidatemaster\">candidatecandidatemaster</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Coreopsis\" title=\"Specialist Coreopsis\">Coreopsis</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/iFFT\" title=\"Expert iFFT\">iFFT</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/Dorothy__\" title=\"Expert Dorothy__\">Dorothy__</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/wfoifysaasisufgv\" title=\"Newbie wfoifysaasisufgv\">wfoifysaasisufgv</a></p></li> </ol><p><strong>Div. 1</strong></p> <ol> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/arvindf232\" title=\"Legendary Grandmaster arvindf232\"><span class=\"legendary-user-first-letter\">a</span>rvindf232</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Rubikun\" title=\"International Grandmaster Rubikun\">Rubikun</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Vercingetorix\" title=\"International Grandmaster Vercingetorix\">Vercingetorix</a></p></li> </ol><p><strong>UPD3.</strong> <a href=\"https://codeforces.com/blog/entry/120353\">Editorial.</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120240\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1867\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 897 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230855-120865\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230855\",\n blogEntryId: \"120240\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+280</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/salyg1n\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/salyg1n\">\n salyg1n\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120240#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120240#comments\">\n 218\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n\r\n<div class=\"pagination\">\r\n <ul>\r\n <span class=\"inactive\">←</span>\r\n <li>\r\n <span class=\"page-index active\" pageIndex=\"1\"><a href=\"/page/1\">1</a></span>\r\n </li>\r\n <li>\r\n <span class=\"page-index\" pageIndex=\"2\"><a href=\"/page/2\">2</a></span>\r\n </li>\r\n <li>\r\n <span 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Burglar and Matches"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Burglar and Matches</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A burglar got into a matches warehouse and wants to steal as many matches as possible. In the warehouse there are <span class=\"tex-span\"><i>m</i></span> containers, in the <span class=\"tex-span\"><i>i</i></span>-th container there are <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> matchboxes, and each matchbox contains <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> matches. All the matchboxes are of the same size. The burglar's rucksack can hold <span class=\"tex-span\"><i>n</i></span> matchboxes exactly. Your task is to find out the maximum amount of matches that a burglar can carry away. He has no time to rearrange matches in the matchboxes, that's why he just chooses not more than <span class=\"tex-span\"><i>n</i></span> matchboxes so that the total amount of matches in them is maximal.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2ยท10<sup class=\"upper-index\">8</sup></span>) and integer <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>m</i>โโคโ20</span>). The <span class=\"tex-span\"><i>i</i>โ+โ1</span>-th line contains a pair of numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">8</sup>,โ1โโคโ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10</span>). All the input numbers are integer.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only number โ answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>7 3<br/>5 10<br/>2 5<br/>3 6<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>62<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 3<br/>2 2<br/>3 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"69b18e2169fb64b67c4a94f6e4aab197\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"09c09aef8ad5be2498175d65869f04dcf51f7d0b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/16\">Codeforces Beta Round 16 (Div. 2 Only)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/16/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='69b18e2169fb64b67c4a94f6e4aab197'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"73\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='69b18e2169fb64b67c4a94f6e4aab197'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"73\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 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OPENING_SPACE = String.fromCharCode(1001);\r\n const CLOSING_SPACE = String.fromCharCode(1002);\r\n\r\n const nodeToText = function (node, pre) {\r\n let result = [];\r\n\r\n if (node.tagName === \"SCRIPT\" || node.tagName === \"math\"\r\n || (node.classList && node.classList.contains(\"input-output-copier\")))\r\n return [];\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(OPENING_SPACE);\r\n }\r\n\r\n if (node.nodeType === Node.TEXT_NODE) {\r\n let s = node.textContent;\r\n if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_340e8adbfbdcb4cf817056bebd3222e09c21c54a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Burglar and Matches</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>A burglar got into a matches warehouse and wants to steal as many matches as possible. In the warehouse there are <span class=\"tex-span\"><i>m</i></span> containers, in the <span class=\"tex-span\"><i>i</i></span>-th container there are <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> matchboxes, and each matchbox contains <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> matches. All the matchboxes are of the same size. The burglar's rucksack can hold <span class=\"tex-span\"><i>n</i></span> matchboxes exactly. Your task is to find out the maximum amount of matches that a burglar can carry away. He has no time to rearrange matches in the matchboxes, that's why he just chooses not more than <span class=\"tex-span\"><i>n</i></span> matchboxes so that the total amount of matches in them is maximal.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2ยท10<sup class=\"upper-index\">8</sup></span>) and integer <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>m</i>โโคโ20</span>). The <span class=\"tex-span\"><i>i</i>โ+โ1</span>-th line contains a pair of numbers <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">8</sup>,โ1โโคโ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10</span>). All the input numbers are integer.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only number โ answer to the problem.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>7 3<br />5 10<br />2 5<br />3 6<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>62<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 3<br />2 2<br />3 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = 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\"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n 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clazz.substr(\"test-example-line-\".length);\r\n if (end !== \"even\" && end !== \"odd\" && end !== \"0\") {\r\n let top = 1E20;\r\n let left = 1E20;\r\n let problem = $(this).closest(\".problemindexholder\");\r\n $(this).closest(\".input\").find(\".\" + clazz).css(\"background-color\", \"#FFFDE7\").each(function() {\r\n top = Math.min(top, $(this).offset().top);\r\n left = Math.min(left, $(this).offset().left);\r\n });\r\n let testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n if (testCaseMarker.length === 0) {\r\n const html = \"<div class=\\\"testCaseMarker testCaseMarker_\" + end + \" notice\\\"></div>\";\r\n problem.append($(html));\r\n testCaseMarker = problem.find(\".testCaseMarker_\" + end);\r\n }\r\n if (testCaseMarker) {\r\n testCaseMarker.show()\r\n .offset({top, left: left - 20})\r\n .text(end);\r\n }\r\n }\r\n }\r\n });\r\n }, function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === 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class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2e03790445a5a5b0be02ccd5f8aaf33e'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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class=\"title\">\r\n <a href=\"/blog/entry/121025\"> <p>Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a>,\r\n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\"logo\" src=\"/predownloaded/e3/33/e333915aebea955b43b4ad17845f6dbf58875a0c.png\" style=\"float: right;height: 100.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></p><p>Sugeng enjing, <strong>Codeforces</strong>! ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ</p><p>COMPFEST 15 is happy to invite you to participate in <a href=\"/contest/1876\" title=\"Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)</a> and <a href=\"/contest/1877\" title=\"Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)</a> on <a class=\"contest-time\" contestid=\"1876\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=8&month=10&year=2023&hour=12&min=5&sec=0&p1=166\"><span class=\"format-time-with-dow\">Oct/08/2023 12:05 (Moscow time)</span></a>. Both rounds will be <strong>rated</strong>. You will be given <strong>2 hours and 30 minutes</strong> to solve <strong>7 problems</strong>.</p><h2><strong>Note the unusual time of the round</strong>.</h2><p>The problems are written by <a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-red\" href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\">Pyqe</a>, and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a>.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-legendary\" href=\"/profile/KAN\" title=\"Legendary Grandmaster KAN\"><span class=\"legendary-user-first-letter\">K</span>AN</a> for helping to host the round;</li> <li><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> and <a class=\"rated-user user-orange\" href=\"/profile/ScarletS\" title=\"Master ScarletS\">ScarletS</a> for the based coordination;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/gansixeneh\" title=\"Candidate Master gansixeneh\">gansixeneh</a> and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a> for helping with the problem preparation;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-blue\" href=\"/profile/CyberSleeper\" title=\"Expert CyberSleeper\">CyberSleeper</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Edbert.H\" title=\"Expert Edbert.H\">Edbert.H</a> for providing alternate solutions in the early stages;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for writing the Russian translations;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Aaeria\" title=\"Master Aaeria\">Aaeria</a>, <a class=\"rated-user user-blue\" href=\"/profile/AMnu\" title=\"Expert AMnu\">AMnu</a>, <a class=\"rated-user user-orange\" href=\"/profile/Berted\" title=\"Master Berted\">Berted</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-cyan\" href=\"/profile/buffering\" title=\"Specialist buffering\">buffering</a>, <a class=\"rated-user user-orange\" href=\"/profile/Drew_\" title=\"Master Drew_\">Drew_</a>, <a class=\"rated-user user-legendary\" href=\"/profile/dorijanlendvaj\" title=\"Legendary Grandmaster dorijanlendvaj\"><span class=\"legendary-user-first-letter\">d</span>orijanlendvaj</a>, <a class=\"rated-user user-orange\" href=\"/profile/eggag32\" title=\"Master eggag32\">eggag32</a>, <a class=\"rated-user user-violet\" href=\"/profile/Elben85\" title=\"Candidate Master Elben85\">Elben85</a>, <a class=\"rated-user user-red\" href=\"/profile/emorgan5289\" title=\"International Grandmaster emorgan5289\">emorgan5289</a>, <a class=\"rated-user user-orange\" href=\"/profile/faustaadp\" title=\"Master faustaadp\">faustaadp</a>, <a class=\"rated-user user-red\" href=\"/profile/ffao\" title=\"International Grandmaster ffao\">ffao</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-legendary\" href=\"/profile/gamegame\" title=\"Legendary Grandmaster gamegame\"><span class=\"legendary-user-first-letter\">g</span>amegame</a>, <a class=\"rated-user user-violet\" href=\"/profile/hocky\" title=\"Candidate Master hocky\">hocky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Insta-x\" title=\"Expert Insta-x\">Insta-x</a>, <a class=\"rated-user user-red\" href=\"/profile/jdurie\" title=\"Grandmaster jdurie\">jdurie</a>, <a class=\"rated-user user-orange\" href=\"/profile/joelgun14\" title=\"Master joelgun14\">joelgun14</a>, <a class=\"rated-user user-violet\" href=\"/profile/KerakTelor\" title=\"Candidate Master KerakTelor\">KerakTelor</a>, <a class=\"rated-user user-blue\" href=\"/profile/Marky\" title=\"Expert Marky\">Marky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Murinh0\" title=\"Expert Murinh0\">Murinh0</a>, <a class=\"rated-user user-red\" href=\"/profile/nvmdava\" title=\"Grandmaster nvmdava\">nvmdava</a>, <a class=\"rated-user user-orange\" href=\"/profile/nyab\" title=\"Master nyab\">nyab</a>, <a class=\"rated-user user-orange\" href=\"/profile/Owmicron\" title=\"Master Owmicron\">Owmicron</a>, <a class=\"rated-user user-red\" href=\"/profile/prvocislo\" title=\"Grandmaster prvocislo\">prvocislo</a>, <a class=\"rated-user user-red\" href=\"/profile/PurpleCrayon\" title=\"International Grandmaster PurpleCrayon\">PurpleCrayon</a>, <a class=\"rated-user user-red\" href=\"/profile/rama_pang\" title=\"Grandmaster rama_pang\">rama_pang</a>, <a class=\"rated-user user-blue\" href=\"/profile/TakeMe\" title=\"Expert TakeMe\">TakeMe</a>, <a class=\"rated-user user-blue\" href=\"/profile/sahil_k\" title=\"Expert sahil_k\">sahil_k</a>, <a class=\"rated-user user-red\" href=\"/profile/user202729_\" title=\"International Grandmaster user202729_\">user202729_</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-green\" href=\"/profile/WHCPP\" title=\"Pupil WHCPP\">WHCPP</a>, and <a class=\"rated-user user-violet\" href=\"/profile/ZeroScar\" title=\"Candidate Master ZeroScar\">ZeroScar</a> for testing the contest and providing us very useful feedback;</li> <li>Universitas Indonesia, all the local committees, administrators, and managers of the whole COMPFEST event;</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Codeforces and Polygon platform!</li> </ul><p>COMPFEST itself is an annual event hosted by Universitas Indonesia. It is the largest student-run IT event in Indonesia and competitive programming contest is one of the competitions hosted.</p><p>We hope you will enjoy and have fun in the contest. Muga-muga beja lan isa entuk biji apik!! ๐ช๐ช๐ฅ๐ฅ</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121025\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1876\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1877\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final 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of complaintReasons) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", complaintReason.id);\n $li.find(\"span\")\n .html(getLocalizedName(complaintReason)\n + \" <i class=\\\"icon-question-sign clickable-title\\\" title=\\\"\"\n + getLocalizedDescription(complaintReason)\n + \"\\\"></i>\")\n .attr(\"title\", getLocalizedDescription(complaintReason));\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n if (complaint && complaint.complaintReasonId === complaintReason.id) {\n $li.find(\"input[name=complaintReasonId]\").attr(\"checked\", \"checked\");\n }\n $li.find(\".clickable-title\").click(function () {\n alert(getLocalizedDescription(complaintReason));\n return false;\n }).css(\"position\", \"relative\").css(\"bottom\", \"1px\").css(\"font-size\", \"12px\");\n }\n\n if (complaint) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", 0);\n $li.find(\"span\").html(\"Delete complaint\");\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n }\n\n $popup.find(\"._ComplaintFrame_submitForm\").submit(function () {\n const complaintReasonId = $popup.find(\"input[name=complaintReasonId]:checked\").val();\n if (complaintReasonId === undefined) {\n alert(\"Please select complaint reason\");\n return false;\n }\n\n $.post(\"/data/complaint\", {\n action: \"newComplaint\",\n targetClass: targetClass,\n targetId: targetId,\n complaintReasonId: complaintReasonId\n }, function (response) {\n if (response.success === \"true\") {\n Codeforces.showMessage(\"Complaint has been created\");\n $.facebox.close();\n }\n }, \"json\");\n\n return false;\n });\n }\n }, \"json\");\n\n return false;\n });\n}); </script>\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Pyqe\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Pyqe\">\n Pyqe\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121025#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121025#comments\">\n 41\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121739\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/121114\"> <p>Codeforces Command Lines (2023-10-06)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\" class=\"rated-user user-blue\">Vladosiya</a>,\r\n <a href=\"/topic/121739/en7\">history</a>,\r\n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>We've compiled a list of command lines that Codeforces uses to compile and run solutions in various languages and compilers.</p><p>It is up-to-date as of today (2023-10-06), and we will make efforts to keep it current in the future, but this is not guaranteed.</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121114\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-73866-121739\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"73866\",\n blogEntryId: \"121114\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compilers\" class=\"tag notice\" style=\"text-decoration: none;\">compilers</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compiler+options\" class=\"tag notice\" style=\"text-decoration: none;\">compiler options</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=languages\" class=\"tag notice\" style=\"text-decoration: none;\">languages</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+235</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n <div style=\"position: relative; float: left; left: -1.5rem; top: 1rem;\">\r\n\n\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Vladosiya\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Vladosiya\">\n Vladosiya\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121114#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121114#comments\">\n 8\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121449\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120824\"> <p>Codeforces Round 901 (Div. 1, Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a>,\r\n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I'm pleased to invite you to <a href=\"/contest/1874\" title=\"Codeforces Round 901 (Div. 1)\">Codeforces Round 901 (Div. 1)</a> and <a href=\"/contest/1875\" title=\"Codeforces Round 901 (Div. 2)\">Codeforces Round 901 (Div. 2)</a>. It starts on <a class=\"contest-time\" contestid=\"1874\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=30&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/30/2023 17:35 (Moscow time)</span></a>. It also means, the National Day of China arrives during the round. Wish you a nice vacation! ๐๐๐</p><p>For both divisions, you will have <strong>3 hours</strong> to solve <strong>7 problems</strong>.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his wonderful coordination.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for Russian translation and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for helping us with Russian clarifications.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\">GeZhiyuan</a> for providing all the problems and "a few" rejected problems.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> and <a class=\"rated-user user-red\" href=\"/profile/SanweiTreap\" title=\"Grandmaster SanweiTreap\">SanweiTreap</a> for helping me prepare the problems.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a>, <a class=\"rated-user user-legendary\" href=\"/profile/wangziji\" title=\"Legendary Grandmaster wangziji\"><span class=\"legendary-user-first-letter\">w</span>angziji</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> and <a class=\"rated-user user-legendary\" href=\"/profile/flowerletter\" title=\"Legendary Grandmaster flowerletter\"><span class=\"legendary-user-first-letter\">f</span>lowerletter</a> for Legendary Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/sjcsjcsjc\" title=\"International Grandmaster sjcsjcsjc\">sjcsjcsjc</a>, <a class=\"rated-user user-red\" href=\"/profile/He_Ren\" title=\"International Grandmaster He_Ren\">He_Ren</a>, <a class=\"rated-user user-red\" href=\"/profile/GaryZ005\" title=\"International Grandmaster GaryZ005\">GaryZ005</a>, <a class=\"rated-user user-red\" href=\"/profile/platelet\" title=\"International Grandmaster platelet\">platelet</a>, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a>, <a class=\"rated-user user-red\" href=\"/profile/thenymphsofdelphi\" title=\"International Grandmaster thenymphsofdelphi\">thenymphsofdelphi</a>, <a class=\"rated-user user-red\" href=\"/profile/DerekFeng\" title=\"International Grandmaster DerekFeng\">DerekFeng</a>, <a class=\"rated-user user-red\" href=\"/profile/Juanzhang\" title=\"International Grandmaster Juanzhang\">Juanzhang</a> and <a class=\"rated-user user-red\" href=\"/profile/ttklwxx\" title=\"International Grandmaster ttklwxx\">ttklwxx</a> for International Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/juju527\" title=\"Grandmaster juju527\">juju527</a>, <a class=\"rated-user user-red\" href=\"/profile/zimpha\" title=\"Grandmaster zimpha\">zimpha</a>, <a class=\"rated-user user-red\" href=\"/profile/765\" title=\"Grandmaster 765\">765</a>, <a class=\"rated-user user-red\" href=\"/profile/xuanquang1999\" title=\"Grandmaster xuanquang1999\">xuanquang1999</a>, <a class=\"rated-user user-red\" href=\"/profile/CrTsIr\" title=\"Grandmaster CrTsIr\">CrTsIr</a> and <a class=\"rated-user user-red\" href=\"/profile/EasonTAO\" title=\"Grandmaster EasonTAO\">EasonTAO</a> for Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/SATSKY\" title=\"Master SATSKY\">SATSKY</a>, <a class=\"rated-user user-orange\" href=\"/profile/lanhf\" title=\"Master lanhf\">lanhf</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hank2019\" title=\"Master Hank2019\">Hank2019</a> and <a class=\"rated-user user-orange\" href=\"/profile/Yakumo_Ran\" title=\"Master Yakumo_Ran\">Yakumo_Ran</a> for Master Testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/DaniraSilla\" title=\"Candidate Master DaniraSilla\">DaniraSilla</a> and <a class=\"rated-user user-violet\" href=\"/profile/kriepiekrollie\" title=\"Candidate Master kriepiekrollie\">kriepiekrollie</a> for Candidate Master Testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/raulandreipop\" title=\"Expert raulandreipop\">raulandreipop</a>, <a class=\"rated-user user-blue\" href=\"/profile/micho\" title=\"Expert micho\">micho</a>, <a class=\"rated-user user-blue\" href=\"/profile/alwyn\" title=\"Expert alwyn\">alwyn</a>, <a class=\"rated-user user-blue\" href=\"/profile/ArgintLaAnu\" title=\"Expert ArgintLaAnu\">ArgintLaAnu</a>, <a class=\"rated-user user-blue\" href=\"/profile/IssamOtoz\" title=\"Expert IssamOtoz\">IssamOtoz</a> and <a class=\"rated-user user-blue\" href=\"/profile/jakao\" title=\"Expert jakao\">jakao</a> for Expert Testing.</p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/CLown1331\" title=\"Pupil CLown1331\">CLown1331</a> for Pupil Testing.</p></li> <li><p>You for participating the round.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</p></li> </ul><p>Especially, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his great contribution to the round, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a> for providing user solutions for all the problems, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> for making the announcement and tutorial more readable.</p><p>Finally and most importantly, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> for helping me with everything patiently all the time. This round can't happen without him.</p><p>The main character of the problems will be Jellyfish, a sweet little girl. ๐๐๐</p><p>Score distribution:</p> <ul> <li><p>Div.1: $$$500$$$ โ $$$1250$$$ โ $$$1500$$$ โ $$$2250$$$ โ $$$3000$$$ โ $$$4000$$$ โ $$$5000$$$</p></li> <li><p>Div.2: $$$500$$$ โ $$$1000$$$ โ $$$1000$$$ โ $$$1250$$$ โ $$$2000$$$ โ $$$2250$$$ โ $$$3000$$$</p></li> </ul><p>Good Luck & Have Fun! ๐ฅ๐ฅ๐ฅ</p><p><strong>UPD1:</strong> <a href=\"https://codeforces.com/blog/entry/120943\">Editorial</a> is out.</p><p><strong>UPD2:</strong> Congratulations to the winners!</p> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\"><span class=\"legendary-user-first-letter\">B</span>enq</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Qingyu\" title=\"International Grandmaster Qingyu\">Qingyu</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/amiya\" title=\"Legendary Grandmaster amiya\"><span class=\"legendary-user-first-letter\">a</span>miya</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/RollingPanda\" title=\"Newbie RollingPanda\">RollingPanda</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/WanYuanShenWanDe\" title=\"Newbie WanYuanShenWanDe\">WanYuanShenWanDe</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-red\" href=\"/profile/H_stove\" title=\"Grandmaster H_stove\">H_stove</a></p><p>B. <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>C. <a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></p><p>D. <a class=\"rated-user user-red\" href=\"/profile/ooOAM\" title=\"Grandmaster ooOAM\">ooOAM</a></p><p>E. <a class=\"rated-user user-orange\" href=\"/profile/Salley-Garden\" title=\"Master Salley-Garden\">Salley-Garden</a></p><p>F. <a class=\"rated-user user-red\" href=\"/profile/i_will_be_less_than_blue\" title=\"Grandmaster i_will_be_less_than_blue\">i_will_be_less_than_blue</a></p><p>G. <a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a> (after the contest)</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-blue\" href=\"/profile/Azaml\" title=\"Expert Azaml\">Azaml</a></p><p>B. <a class=\"rated-user user-blue\" href=\"/profile/Shirotsume\" title=\"Expert Shirotsume\">Shirotsume</a></p><p>C. <a class=\"rated-user user-gray\" href=\"/profile/viveksingh912\" title=\"Newbie viveksingh912\">viveksingh912</a></p><p>D. <a class=\"rated-user user-gray\" href=\"/profile/kaiboy\" title=\"Newbie kaiboy\">kaiboy</a></p><p>E. <a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p><p>F. <a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p><p>G. <a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></div></div></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120824\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1874\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1875\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-238039-121449\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"238039\",\n blogEntryId: \"120824\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+165</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/GeZhiyuan\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/GeZhiyuan\">\n GeZhiyuan\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120824#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120824#comments\">\n 231\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121303\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120678\"> <p>Codeforces Round #900 (Div. 3)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AlphaMale06\" title=\"Specialist AlphaMale06\" class=\"rated-user user-cyan\">AlphaMale06</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p><a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a> and I are glad to invite you to the <a href=\"/contest/1878\" title=\"Codeforces Round 900 (Div. 3)\">Codeforces Round 900 (Div. 3)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1878\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=26&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/26/2023 17:35 (Moscow time)</span></a></p><p>You will be given <strong>7 problems</strong> and <strong>2 hours and 15 minutes</strong> to solve them.</p><p>Note that the <strong>penalty</strong> for the wrong submission in this round is <strong>10 minutes</strong>.</p><p>Also note that there will be a <strong>12 hour open hacking phase</strong> after the round.</p><p><a href=\"https://codeforces.com/blog/entry/59228\">Remember</a>, that only the <em>trusted participants of the third division</em> will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a <em>trusted participant of the third division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them)</li> <li>do not have a point of 1900 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, the round will be rated for you.</strong></p><p>Problems have been created and prepared by <a class=\"rated-user user-blue\" href=\"/profile/AlphaMale06\" title=\"Expert AlphaMale06\">AlphaMale06</a>, <a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>.</p><p>We would also to thank:</p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for the amazing coordination and help with preparing a balanced problemset, and for giving us the opportunity to create a Div. 3 round.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Polygon and Codeforces platforms.</li> <li><a class=\"rated-user user-red\" href=\"/profile/JovanB\" title=\"Grandmaster JovanB\">JovanB</a>, <a class=\"rated-user user-red\" href=\"/profile/abc864197532\" title=\"International Grandmaster abc864197532\">abc864197532</a>, <a class=\"rated-user user-red\" href=\"/profile/sevlll777\" title=\"Grandmaster sevlll777\">sevlll777</a> for red testing</li> <li><a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>, <a class=\"rated-user user-orange\" href=\"/profile/n0sk1ll\" title=\"Master n0sk1ll\">n0sk1ll</a>, <a class=\"rated-user user-orange\" href=\"/profile/allllekssssa\" title=\"Master allllekssssa\">allllekssssa</a>, <a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a>, <a class=\"rated-user user-orange\" href=\"/profile/misorin\" title=\"International Master misorin\">misorin</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hyperbolic\" title=\"International Master Hyperbolic\">Hyperbolic</a> for yellow testing</li> <li><a class=\"rated-user user-violet\" href=\"/profile/DAleksa\" title=\"Candidate Master DAleksa\">DAleksa</a>, <a class=\"rated-user user-violet\" href=\"/profile/ljuba\" title=\"Candidate Master ljuba\">ljuba</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex.kudryashov\" title=\"Candidate Master alex.kudryashov\">alex.kudryashov</a> for purple testing</li> <li><a class=\"rated-user user-blue\" href=\"/profile/MihailoT\" title=\"Expert MihailoT\">MihailoT</a>, <a class=\"rated-user user-blue\" href=\"/profile/SashaT9\" title=\"Expert SashaT9\">SashaT9</a>, <a class=\"rated-user user-blue\" href=\"/profile/ELDRVD\" title=\"Expert ELDRVD\">ELDRVD</a>, <a class=\"rated-user user-blue\" href=\"/profile/Chrisedyong\" title=\"Expert Chrisedyong\">Chrisedyong</a>, <a class=\"rated-user user-blue\" href=\"/profile/tryptophan\" title=\"Expert tryptophan\">tryptophan</a> for blue testing</li> <li><a class=\"rated-user user-cyan\" href=\"/profile/Andrijanikolic73\" title=\"Specialist Andrijanikolic73\">Andrijanikolic73</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Mihajlo18\" title=\"Specialist Mihajlo18\">Mihajlo18</a>, <a class=\"rated-user user-cyan\" href=\"/profile/UrosNedic\" title=\"Specialist UrosNedic\">UrosNedic</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Klaus26\" title=\"Specialist Klaus26\">Klaus26</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Escaquejant\" title=\"Specialist Escaquejant\">Escaquejant</a>, <a class=\"rated-user user-cyan\" href=\"/profile/smax294\" title=\"Specialist smax294\">smax294</a>, <a class=\"rated-user user-cyan\" href=\"/profile/max0n\" title=\"Specialist max0n\">max0n</a> for cyan testing</li> <li><a class=\"rated-user user-gray\" href=\"/profile/Budimmm\" title=\"Newbie Budimmm\">Budimmm</a> for gray testing</li> </ol><p>Also a very special thanks to the most dedicated tester I have ever seen, <a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>.</p><p>I wish you luck, and hope you like the problems and learn from them.</p><p>Update: <a href=\"https://codeforces.com/blog/entry/120813\">Editorial</a> is out.</p><p>Congratulations to the winners:</p><p>Unofficial:</p> <ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/SSerxhs\" title=\"International Grandmaster SSerxhs\">SSerxhs</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/neal\" title=\"Legendary Grandmaster neal\"><span class=\"legendary-user-first-letter\">n</span>eal</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/risujiroh\" title=\"International Grandmaster risujiroh\">risujiroh</a></p></li> </ol><p>Official:</p> <ol> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/hackerjohn\" title=\"Specialist hackerjohn\">hackerjohn</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/wahb\" title=\"Specialist wahb\">wahb</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/kutcoder\" title=\"Specialist kutcoder\">kutcoder</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Sxy_Limit\" title=\"Specialist Sxy_Limit\">Sxy_Limit</a></p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/not_rainboy\" title=\"Pupil not_rainboy\">not_rainboy</a></p></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120678\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1878\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 900 (Div. 3)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-269459-121303\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"269459\",\n blogEntryId: \"120678\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+192</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AlphaMale06\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AlphaMale06\">\n AlphaMale06\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120678#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120678#comments\">\n 347\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121269\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120644\"> <p>Codeforces Round 899 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a>,\r\n <a href=\"/topic/121269/en9\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I am pleased to invite you to participate in <a href=\"/contest/1882\" title=\"Codeforces Round 899 (Div. 2)\">Codeforces Round 899 (Div. 2)</a>, which will be held on <a class=\"contest-time\" contestid=\"1882\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=25&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/25/2023 17:35 (Moscow time)</span></a>.</p><p>All problems were written and prepared by me.</p><p>You will be given <strong>5 problems, and one of them is divided into two subtasks</strong>. You will have <strong>2 hours</strong> to solve them.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-orange\" href=\"/profile/irkstepanov\" title=\"International Master irkstepanov\">irkstepanov</a> for excellent coordination and Russian translation!</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for providing useful feedbacks.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a> for helping me much with one problem of the contest.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/ko_osaga\" title=\"Legendary Grandmaster ko_osaga\"><span class=\"legendary-user-first-letter\">k</span>o_osaga</a> for Nutella testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/leinad2\" title=\"Grandmaster leinad2\">leinad2</a>, <a class=\"rated-user user-red\" href=\"/profile/Numbering\" title=\"Grandmaster Numbering\">Numbering</a>, <a class=\"rated-user user-red\" href=\"/profile/qwerasdfzxcl\" title=\"International Grandmaster qwerasdfzxcl\">qwerasdfzxcl</a>, <a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a>, <a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for Red testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Kaling\" title=\"Master Kaling\">Kaling</a>, <a class=\"rated-user user-orange\" href=\"/profile/Mingyu331\" title=\"Master Mingyu331\">Mingyu331</a>, <a class=\"rated-user user-orange\" href=\"/profile/chaeyihwan\" title=\"International Master chaeyihwan\">chaeyihwan</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kawaii2DIdolOfGSHS\" title=\"International Master Kawaii2DIdolOfGSHS\">Kawaii2DIdolOfGSHS</a>, <a class=\"rated-user user-orange\" href=\"/profile/azberjibiou\" title=\"International Master azberjibiou\">azberjibiou</a>, <a class=\"rated-user user-orange\" href=\"/profile/mjhmjh1104\" title=\"Master mjhmjh1104\">mjhmjh1104</a>, <a class=\"rated-user user-orange\" href=\"/profile/DELTARUNE\" title=\"Master DELTARUNE\">DELTARUNE</a>, <a class=\"rated-user user-orange\" href=\"/profile/wuhudsm\" title=\"Master wuhudsm\">wuhudsm</a>, <a class=\"rated-user user-orange\" href=\"/profile/hypergraph_coloring\" title=\"International Master hypergraph_coloring\">hypergraph_coloring</a> for Orange testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/unordered_map\" title=\"Candidate Master unordered_map\">unordered_map</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex0211\" title=\"Candidate Master alex0211\">alex0211</a>, <a class=\"rated-user user-violet\" href=\"/profile/gs20036\" title=\"Candidate Master gs20036\">gs20036</a>, <a class=\"rated-user user-violet\" href=\"/profile/namolbbaemi\" title=\"Candidate Master namolbbaemi\">namolbbaemi</a>, <a class=\"rated-user user-violet\" href=\"/profile/eeeDA\" title=\"Candidate Master eeeDA\">eeeDA</a>, <a class=\"rated-user user-violet\" href=\"/profile/nlog\" title=\"Candidate Master nlog\">nlog</a> for Purple testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/andyandy\" title=\"Expert andyandy\">andyandy</a>, <a class=\"rated-user user-blue\" href=\"/profile/JaewonOh\" title=\"Expert JaewonOh\">JaewonOh</a>, <a class=\"rated-user user-blue\" href=\"/profile/KongUm\" title=\"Expert KongUm\">KongUm</a>, <a class=\"rated-user user-blue\" href=\"/profile/Coruncanius\" title=\"Expert Coruncanius\">Coruncanius</a>, <a class=\"rated-user user-blue\" href=\"/profile/ez_code\" title=\"Expert ez_code\">ez_code</a>, <a class=\"rated-user user-blue\" href=\"/profile/fs_edge\" title=\"Expert fs_edge\">fs_edge</a>, <a class=\"rated-user user-blue\" href=\"/profile/chromate00\" title=\"Expert chromate00\">chromate00</a> for Blue testing.</p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/Hanlana18\" title=\"Newbie Hanlana18\">Hanlana18</a>, <a class=\"rated-user user-gray\" href=\"/profile/papergundam\" title=\"Newbie papergundam\">papergundam</a>, <a class=\"rated-user user-gray\" href=\"/profile/sjmjys954646\" title=\"Newbie sjmjys954646\">sjmjys954646</a> for Gray testing.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for great Polygon and Codeforces platforms!</p></li> <li><p>And last but not least, <a class=\"rated-user user-legendary\" href=\"https://codeforces.com/profile/\">You</a> for participating in the round!</p></li> </ul><p>Score distribution: $$$500 - 1000 - 1500 - 2000 - (2000 + 2000)$$$</p><p>Good luck and enjoy the round!</p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120792\">Editorial</a> is out. </p><p><strong>UPD2</strong>: Congratulations to the winners!</p><p><strong>Official Contestants</strong></p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Lycorisqwq\" title=\"Expert Lycorisqwq\">Lycorisqwq</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/zepto\" title=\"Unrated, zepto\">zepto</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/vjudge39\" title=\"Unrated, vjudge39\">vjudge39</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/Beelzebub_blue\" title=\"Candidate Master Beelzebub_blue\">Beelzebub_blue</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/_t_W_\" title=\"Candidate Master _t_W_\">_t_W_</a></li> </ol><p><strong>Official + Unofficial Contestants</strong></p> <ol> <li><a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/antontrygubO_o\" title=\"International Grandmaster antontrygubO_o\">antontrygubO_o</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a></li> <li><a class=\"rated-user user-orange\" href=\"/profile/KumaTachiRen\" title=\"Master KumaTachiRen\">KumaTachiRen</a></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120644\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1882\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 899 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-272374-121269\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"272374\",\n blogEntryId: \"120644\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+524</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/windva\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/windva\">\n windva\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120644#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120644#comments\">\n 188\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121316\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120691\"> <p>Educational Codeforces Round 155 [Rated for Div. 2]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a>,\r\n <a href=\"/topic/121316/en5\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p>On <a class=\"contest-time\" contestid=\"1879\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=24&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/24/2023 17:35 (Moscow time)</span></a> <a href=\"/contest/1879\" title=\"Educational Codeforces Round 155 (Rated for Div. 2)\">Educational Codeforces Round 155 (Rated for Div. 2)</a> will start.</p><p>Series of Educational Rounds continue being held as <a href=\"https://harbour.space/\">Harbour.Space University</a> initiative! You can read the details about the cooperation between <a href=\"https://harbour.space/\">Harbour.Space University</a> and Codeforces in the <a href=\"https://mirror.codeforces.com/blog/entry/51208\">blog post</a>.</p><p>This round will be <strong>rated for the participants with rating lower than 2100</strong>. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.</p><p>You will be given <strong>6 or 7 problems</strong> and <strong>2 hours</strong> to solve them.</p><p>The problems were invented and prepared by Adilbek <a class=\"rated-user user-orange\" href=\"/profile/adedalic\" title=\"International Master adedalic\">adedalic</a> Dalabaev, Ivan <a class=\"rated-user user-red\" href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\">BledDest</a> Androsov, Maksim <a class=\"rated-user user-violet\" href=\"/profile/Neon\" title=\"Candidate Master Neon\">Neon</a> Mescheryakov, Roman <a class=\"rated-user user-orange\" href=\"/profile/Roms\" title=\"Master Roms\">Roms</a> Glazov and me. Also, huge thanks to Mike <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> Mirzayanov for great systems Polygon and Codeforces.</p><p>Good luck to all the participants!</p><p>Our friends at Harbour.Space also have a message for you:</p> <center><img alt=\"Harbour.Space\" src=\"/predownloaded/29/a4/29a4884273346021dec6559e9785af37a662cc56.png\" style=\"height: 200.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></center> <center style=\"margin: 1.0em;\"><b>FULLY FUNDED SCHOLARSHIPS for Masters in Data Science and Computer Science </b></center><p><em>Scholarships for Master's students in <a href=\"https://harbour.space/computer-science\">Computer Science</a> and <a href=\"https://harbour.space/data-science\">Data Science</a> are available in <a href=\"https://harbour.space\">Harbour.Space University</a> Barcelona campus!</em> </p><p><strong>Scholarship Summary:</strong></p> <ul> <li><em>Fully funded scholarship (29.900 โฌ/year) to study a Masterโs degree in Data Science or Computer Science for two years</em></li> <li><em>Successful applicants will become part of the Universityโs โTalent poolโ and will be shown to the sponsoring companies. In case the candidate is picked for the Work&Study Program from our industry partner, the student starts an internship with a commitment to study 3 hours/day and work for 4 hour/day</em></li> </ul><p><em>Please note preselected candidates will be requested to pay a non-refundable application fee of 85โฌ to study at Harbour.Space University.</em></p><p><em><strong>Candidateโs commitment:</strong></em></p><p><em>You will complete 15 modules (each three weeks long) in one year. The daily class workload is 3 hours, plus homework to complete in your own time.</em></p><p><em><strong>Candidateโs requirements:</strong></em> </p> <ul> <li><em>Bachelor's degree in the field of Mathematics, Statistics, Data Science, Computer Science or similar</em></li> <li><em>English proficiency</em></li> <li><em>Advanced knowledge and experience in Python, SQL, Spark/Scala, and bash</em></li> <li><em>Experienced use of Big Data technologies: Spark, HDFS, Kafka, etc.</em></li> <li><em>Hands-on experience with Data Science techniques: feature engineering,</em></li> <li><em>Strong ML knowledge</em></li> <li><em>Strong Software Engineering Background</em></li> <li><em>Problem-solving aptitude</em></li> </ul> <center style=\"margin: 2.5em;\"> <a href=\"https://harbour.space/account/apply-process?utm_source=codeforces&utm_medium=partner&utm_campaign=bcn_b2b\" style=\"text-decoration: none;font-size: 14.0px;background-color: rgb(98,91,183);color: white;font-weight: bold;padding: 0.5em 1.0em;\">Apply here โ</a> </center><p><strong>UPD:</strong> <a href=\"https://codeforces.com/blog/entry/120773\">Editorial is out</a> </p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120691\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1879\" class=\"notice\" style=\"text-decoration: none;\">Educational Codeforces Round 155 (Rated for Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-42750-121316\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"42750\",\n blogEntryId: \"120691\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+245</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/awoo\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/awoo\">\n awoo\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120691#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120691#comments\">\n 189\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121227\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120602\"> <p>Codeforces Round 898 (Div. 4)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/mesanu\" title=\"Candidate Master mesanu\" class=\"rated-user user-violet\">mesanu</a>,\r\n <a href=\"/topic/121227/en2\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p><a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and I want to invite you to <a href=\"/contest/1873\" title=\"Codeforces Round 898 (Div. 4)\">Codeforces Round 898 (Div. 4)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1873\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=21&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/21/2023 17:35 (Moscow time)</span></a>.</p><p>The format of the event will be identical to Div. 3 rounds:</p> <ul> <li>5-8 tasks;</li> <li>ICPC rules with a penalty of 10 minutes for an incorrect submission;</li> <li>12-hour phase of open hacks after the end of the round (hacks do not give additional points)</li> <li>after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated</li> <li>by default, only "trusted" participants are shown in the results table (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).</li> </ul><p>We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.</p><p>Only <em>trusted participants of the fourth division</em> will be included in the official standings table. This is a forced measure for combating unsporting behaviour. To qualify as <em>a trusted participant of the fourth division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them),</li> <li>do not have a point of 1400 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), then the round will be rated for you.</strong></p><p>Many thanks to the testers: <a class=\"rated-user user-orange\" href=\"/profile/Gheal\" title=\"Master Gheal\">Gheal</a>, <a class=\"rated-user user-orange\" href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\">Phantom_Performer</a>, <a class=\"rated-user user-orange\" href=\"/profile/KrowSavcik\" title=\"Master KrowSavcik\">KrowSavcik</a>, <a class=\"rated-user user-cyan\" href=\"/profile/haochenkang\" title=\"Specialist haochenkang\">haochenkang</a>, <a class=\"rated-user user-cyan\" href=\"/profile/sandry24\" title=\"Specialist sandry24\">sandry24</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>, <a class=\"rated-user user-violet\" href=\"/profile/NintsiChkhaidze\" title=\"Candidate Master NintsiChkhaidze\">NintsiChkhaidze</a>, <a class=\"rated-user user-orange\" href=\"/profile/erekle\" title=\"International Master erekle\">erekle</a>, <a class=\"rated-user user-red\" href=\"/profile/Dominater069\" title=\"Grandmaster Dominater069\">Dominater069</a>, <a class=\"rated-user user-blue\" href=\"/profile/MADE_IN_HEAVEN\" title=\"Expert MADE_IN_HEAVEN\">MADE_IN_HEAVEN</a>, <a class=\"rated-user user-blue\" href=\"/profile/Qualified\" title=\"Expert Qualified\">Qualified</a>.</p><p>We suggest reading all of the problems and hope you will find them interesting!</p><p><strong>Good Luck!</strong></p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120634\">Editorial is out!</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120602\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1873\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 898 (Div. 4)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-188642-121227\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"188642\",\n blogEntryId: \"120602\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+200</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/mesanu\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/mesanu\">\n mesanu\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120602#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120602#comments\">\n 179\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121083\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120458\"> <p>CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/glebustim\" title=\"Grandmaster glebustim\" class=\"rated-user user-red\">glebustim</a>,\r\n <a href=\"/topic/121083/en8\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3>Hello, Codeforces!</h3><p><a class=\"rated-user user-red\" href=\"/profile/SomethingNew\" title=\"International Grandmaster SomethingNew\">SomethingNew</a> and I are glad to invite you to <a href=\"/contest/1870\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a>, which will take place on <a class=\"contest-time\" contestid=\"1870\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=18&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/18/2023 17:35 (Moscow time)</span></a>. You will have 2 hours 15 minutes to solve 8 problems. The round will be rated for everyone.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-orange\" href=\"/profile/74TrAkToR\" title=\"International Master 74TrAkToR\">74TrAkToR</a> for coordinating this round.</li> <li><a class=\"rated-user user-legendary\" href=\"/profile/isaf27\" title=\"Legendary Grandmaster isaf27\"><span class=\"legendary-user-first-letter\">i</span>saf27</a>, <a class=\"rated-user user-legendary\" href=\"/profile/ugly2333\" title=\"Legendary Grandmaster ugly2333\"><span class=\"legendary-user-first-letter\">u</span>gly2333</a>, <a class=\"rated-user user-red\" href=\"/profile/DataStructures\" title=\"Grandmaster DataStructures\">DataStructures</a>, <a class=\"rated-user user-red\" href=\"/profile/Little09\" title=\"International Grandmaster Little09\">Little09</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kieray\" title=\"Master Kieray\">Kieray</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-orange\" href=\"/profile/Dart-Xeyter\" title=\"International Master Dart-Xeyter\">Dart-Xeyter</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/meowcneil\" title=\"Master meowcneil\">meowcneil</a>, <a class=\"rated-user user-orange\" href=\"/profile/127.0.0.1\" title=\"Master 127.0.0.1\">127.0.0.1</a>, <a class=\"rated-user user-violet\" href=\"/profile/Nanani\" title=\"Candidate Master Nanani\">Nanani</a>, <a class=\"rated-user user-violet\" href=\"/profile/nnv-nick\" title=\"Candidate Master nnv-nick\">nnv-nick</a>, <a class=\"rated-user user-violet\" href=\"/profile/SomethingDifferent\" title=\"Candidate Master SomethingDifferent\">SomethingDifferent</a>, <a class=\"rated-user user-blue\" href=\"/profile/vl342\" title=\"Expert vl342\">vl342</a>, <a class=\"rated-user user-blue\" href=\"/profile/shiv_codegen\" title=\"Expert shiv_codegen\">shiv_codegen</a>, <a class=\"rated-user user-cyan\" href=\"/profile/M1lkas\" title=\"Specialist M1lkas\">M1lkas</a>, <a class=\"rated-user user-green\" href=\"/profile/allmath\" title=\"Pupil allmath\">allmath</a>, <a class=\"rated-user user-gray\" href=\"/profile/sdyakonov\" title=\"Newbie sdyakonov\">sdyakonov</a> for testing the round and providing useful feedback.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</li> </ul><h4><strong>Score distribution:</strong></h4><p>500 โ 750 โ 1500 โ 1750 โ 2750 โ 3250 โ 3250 โ 4000</p><p>We hope that our problems will be interesting for you!</p><h4><a href=\"https://codeforces.com/blog/entry/120524\">Editorial</a></h4><p><strong>Congratulations to the winners!</strong></p> <ol> <li><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/emptyhope\" title=\"Legendary Grandmaster emptyhope\"><span class=\"legendary-user-first-letter\">e</span>mptyhope</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/maspy\" title=\"International Grandmaster maspy\">maspy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/AoLiGei\" title=\"Legendary Grandmaster AoLiGei\"><span class=\"legendary-user-first-letter\">A</span>oLiGei</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/noimi\" title=\"Legendary Grandmaster noimi\"><span class=\"legendary-user-first-letter\">n</span>oimi</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></li> </ol><p>And here is the information from our title sponsor:</p><p><img src=\"/predownloaded/ce/9f/ce9f87d5c429f47e7691bef3a8934ebf36af3f15.jpg\" style=\"width: 250.0px;float: right;margin: 0 1.0em 1.0em 1.0em;max-width: 100.0%;max-height: 100.0%;\" /></p><p><em>Hello, Codeforces!</em></p><p><em>We, the <a href=\"https://ton.org/\">TON Foundation</a> team, are pleased to support CodeTON Round 6.</em></p><p><em>The Open Network (TON) is a fully decentralized layer-1 blockchain designed to onboard billions of users to Web3.</em></p><p><em>Since July 2022, <a href=\"/blog/entry/104544\">we have been supporting</a> Codeforces as a title sponsor. This round is another way for us to contribute to the development of the community.</em></p><p><em>The winners of CodeTON Round 6 will receive valuable prizes.</em></p><p><em>The first 1,023 participants will receive prizes in TON cryptocurrency:</em></p> <ul> <li><em>1st place: 1,024 TON</em></li> <li><em>2โ3 places: 512 TON each</em></li> <li><em>4โ7 places: 256 TON each</em></li> <li><em>8โ15 places: 128 TON each</em></li> <li><em>โฆ</em></li> <li><em>512โ1,023 places: 2 TON each</em></li> </ul><p><em>We wish you good luck at CodeTON Round 6 and hope you enjoy the contest!</em></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120458\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1870\" class=\"notice\" style=\"text-decoration: none;\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-223600-121083\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"223600\",\n blogEntryId: \"120458\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+394</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/glebustim\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/glebustim\">\n glebustim\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120458#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120458#comments\">\n 171\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"120865\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120240\"> <p>Codeforces Round #897 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/salyg1n\" title=\"Master salyg1n\" class=\"rated-user user-orange\">salyg1n</a>,\r\n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces! ๐คฏ</p><p><a class=\"rated-user user-red\" href=\"/profile/green_gold_dog\" title=\"Grandmaster green_gold_dog\">green_gold_dog</a>, <a class=\"rated-user user-orange\" href=\"/profile/ace5\" title=\"International Master ace5\">ace5</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> and I <a class=\"rated-user user-orange\" href=\"/profile/salyg1n\" title=\"Master salyg1n\">salyg1n</a> are pleased to invite you to participate in <a href=\"https://codeforces.com/contest/1867\">Codeforces Round 897 (Div. 2)</a>, which will take place on <a href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=11&month=9&year=2023&hour=17&min=35&sec=0&p1=166\">Monday, September 11, 2023 in 17:35</a>.</p><p>This round will be <strong>rated</strong> for participants whose <strong>rating is below 2100</strong>.</p><p>You will be given 6 tasks and 2 hours to solve them. We recommend reading all the tasks. <strong>Interactive tasks may occur in the round</strong>, so we suggest reading this <a href=\"https://codeforces.com/blog/entry/45307\">post</a>.</p><p>We want to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/Aleks5d\" title=\"Grandmaster Aleks5d\">Aleks5d</a> for coordinating the round and improving one of the tasks. ๐ค</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Allvik06\" title=\"International Grandmaster Allvik06\">Allvik06</a>, <a class=\"rated-user user-red\" href=\"/profile/Nutella3000\" title=\"Grandmaster Nutella3000\">Nutella3000</a>, <a class=\"rated-user user-red\" href=\"/profile/arbuzick\" title=\"International Grandmaster arbuzick\">arbuzick</a>, <a class=\"rated-user user-red\" href=\"/profile/alegsandyr\" title=\"Grandmaster alegsandyr\">alegsandyr</a>, <a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/FairyWinx\" title=\"Grandmaster FairyWinx\">FairyWinx</a>, <a class=\"rated-user user-red\" href=\"/profile/zwezdinv\" title=\"Grandmaster zwezdinv\">zwezdinv</a>, <a class=\"rated-user user-orange\" href=\"/profile/valerikk\" title=\"Master valerikk\">valerikk</a>, <a class=\"rated-user user-orange\" href=\"/profile/danya111\" title=\"Master danya111\">danya111</a>, <a class=\"rated-user user-orange\" href=\"/profile/EJIC_B_KEDAX\" title=\"Master EJIC_B_KEDAX\">EJIC_B_KEDAX</a>, <a class=\"rated-user user-orange\" href=\"/profile/dushenkov\" title=\"Master dushenkov\">dushenkov</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/aleksandro\" title=\"Master aleksandro\">aleksandro</a>, <a class=\"rated-user user-orange\" href=\"/profile/Yar_sem\" title=\"Master Yar_sem\">Yar_sem</a>, <a class=\"rated-user user-orange\" href=\"/profile/asafiul\" title=\"Master asafiul\">asafiul</a>, <a class=\"rated-user user-violet\" href=\"/profile/Ivan_len\" title=\"Candidate Master Ivan_len\">Ivan_len</a>, <a class=\"rated-user user-violet\" href=\"/profile/ArtAlex\" title=\"Candidate Master ArtAlex\">ArtAlex</a>, <a class=\"rated-user user-violet\" href=\"/profile/Undying\" title=\"Candidate Master Undying\">Undying</a>, <a class=\"rated-user user-violet\" href=\"/profile/JustNik77\" title=\"Candidate Master JustNik77\">JustNik77</a>, <a class=\"rated-user user-violet\" href=\"/profile/Pavarishko\" title=\"Candidate Master Pavarishko\">Pavarishko</a> and <a class=\"rated-user user-violet\" href=\"/profile/xnor\" title=\"Candidate Master xnor\">xnor</a> for testing the round and giving valuable feedback. ๐ <span style=\"color: rgb(255,255,255);\">orz</span></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/ryskmax\" title=\"Expert ryskmax\">ryskmax</a> for being the only blue tester and giving valuable feedback. ๐ณ </p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/DimaTomsk\" title=\"Master DimaTomsk\">DimaTomsk</a> and <a class=\"rated-user user-orange\" href=\"/profile/ilyakrasnovv\" title=\"Master ilyakrasnovv\">ilyakrasnovv</a> for viewing some of the tasks and giving valuable feedback. ๐ค <span style=\"color: rgb(255,255,255);\"></span></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/stepanov.aa\" title=\"Grandmaster stepanov.aa\">stepanov.aa</a> for <strong>not</strong> testing the round. ๐ฆฅ <span style=\"color: rgb(255,255,255);\">:(</span></p></li> <li><p>The authors of the task <em>5. Overtaking</em> from IOI 2023 for <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> taking a <strong>gold medal</strong>. ๐ฅ <span style=\"color: rgb(255,255,255);\">Too dead? Yes, so am I.</span></p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and <a class=\"rated-user user-admin\" href=\"/profile/geranazavr555\" title=\"Headquarters, geranazavr555\">geranazavr555</a> for the excellent codeforces and polygon platforms. ๐ฆ <span style=\"color: rgb(255,255,255);\">Thank you!</span></p></li> </ul><p>We hope you'll enjoy our problems! Good luck!</p><p><strong>UPD.</strong> Score distribution: $$$500 - 1000 - 1250 - 2000 - (2000 + 1000) - 4000$$$.</p><p><strong>UPD2.</strong> Congratulations to the winners!</p><p><strong>Div. 2</strong></p> <ol> <li><p><a class=\"rated-user user-violet\" href=\"/profile/candidatecandidatemaster\" title=\"Candidate Master candidatecandidatemaster\">candidatecandidatemaster</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Coreopsis\" title=\"Specialist Coreopsis\">Coreopsis</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/iFFT\" title=\"Expert iFFT\">iFFT</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/Dorothy__\" title=\"Expert Dorothy__\">Dorothy__</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/wfoifysaasisufgv\" title=\"Newbie wfoifysaasisufgv\">wfoifysaasisufgv</a></p></li> </ol><p><strong>Div. 1</strong></p> <ol> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/arvindf232\" title=\"Legendary Grandmaster arvindf232\"><span class=\"legendary-user-first-letter\">a</span>rvindf232</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Rubikun\" title=\"International Grandmaster Rubikun\">Rubikun</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Vercingetorix\" title=\"International Grandmaster Vercingetorix\">Vercingetorix</a></p></li> </ol><p><strong>UPD3.</strong> <a href=\"https://codeforces.com/blog/entry/120353\">Editorial.</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120240\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1867\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 897 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230855-120865\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230855\",\n blogEntryId: \"120240\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+280</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/salyg1n\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/salyg1n\">\n salyg1n\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120240#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120240#comments\">\n 218\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n\r\n<div class=\"pagination\">\r\n <ul>\r\n <span class=\"inactive\">←</span>\r\n <li>\r\n <span class=\"page-index active\" pageIndex=\"1\"><a href=\"/page/1\">1</a></span>\r\n </li>\r\n <li>\r\n <span class=\"page-index\" pageIndex=\"2\"><a href=\"/page/2\">2</a></span>\r\n </li>\r\n <li>\r\n <span 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Monitor"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Monitor</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Reca company makes monitors, the most popular of their models is AB999 with the screen size <span class=\"tex-span\"><i>a</i>โรโ<i>b</i></span> centimeters. Because of some production peculiarities a screen parameters are integer numbers. Recently the screen sides ratio <span class=\"tex-span\"><i>x</i>:โ<i>y</i></span> became popular with users. That's why the company wants to reduce monitor AB999 size so that its screen sides ratio becomes <span class=\"tex-span\"><i>x</i>:โ<i>y</i></span>, at the same time they want its total area to be maximal of all possible variants. Your task is to find the screen parameters of the reduced size model, or find out that such a reduction can't be performed.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains 4 integers โ <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> (<span class=\"tex-span\">1โโคโ<i>a</i>,โ<i>b</i>,โ<i>x</i>,โ<i>y</i>โโคโ2ยท10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the answer exists, output 2 positive integers โ screen parameters of the reduced size model. Output <span class=\"tex-font-style-tt\">0 0</span> otherwise.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>800 600 4 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>800 600<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1920 1200 16 9<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1920 1080<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 1 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0 0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"972cd635f59959951bfae03f2cb6c0b4\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"09c09aef8ad5be2498175d65869f04dcf51f7d0b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='972cd635f59959951bfae03f2cb6c0b4'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/16/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='972cd635f59959951bfae03f2cb6c0b4'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"74\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='972cd635f59959951bfae03f2cb6c0b4'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"74\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/422\" title=\"Codeforces Beta Round #16 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"96:97\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/431\" title=\"Codeforces Beta Round #16 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"706:707\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/16\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/16/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/16/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/16/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/16/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/16/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: 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diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Monitor</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Reca company makes monitors, the most popular of their models is AB999 with the screen size <span class=\"tex-span\"><i>a</i>โรโ<i>b</i></span> centimeters. Because of some production peculiarities a screen parameters are integer numbers. Recently the screen sides ratio <span class=\"tex-span\"><i>x</i>:โ<i>y</i></span> became popular with users. That's why the company wants to reduce monitor AB999 size so that its screen sides ratio becomes <span class=\"tex-span\"><i>x</i>:โ<i>y</i></span>, at the same time they want its total area to be maximal of all possible variants. Your task is to find the screen parameters of the reduced size model, or find out that such a reduction can't be performed.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains 4 integers โ <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>x</i></span> and <span class=\"tex-span\"><i>y</i></span> (<span class=\"tex-span\">1โโคโ<i>a</i>,โ<i>b</i>,โ<i>x</i>,โ<i>y</i>โโคโ2ยท10<sup class=\"upper-index\">9</sup></span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the answer exists, output 2 positive integers โ screen parameters of the reduced size model. Output <span class=\"tex-font-style-tt\">0 0</span> otherwise.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>800 600 4 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>800 600<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1920 1200 16 9<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1920 1080<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 1 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0 0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let 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class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2e03790445a5a5b0be02ccd5f8aaf33e'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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class=\"title\">\r\n <a href=\"/blog/entry/121025\"> <p>Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a>,\r\n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\"logo\" src=\"/predownloaded/e3/33/e333915aebea955b43b4ad17845f6dbf58875a0c.png\" style=\"float: right;height: 100.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></p><p>Sugeng enjing, <strong>Codeforces</strong>! ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ</p><p>COMPFEST 15 is happy to invite you to participate in <a href=\"/contest/1876\" title=\"Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)</a> and <a href=\"/contest/1877\" title=\"Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)</a> on <a class=\"contest-time\" contestid=\"1876\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=8&month=10&year=2023&hour=12&min=5&sec=0&p1=166\"><span class=\"format-time-with-dow\">Oct/08/2023 12:05 (Moscow time)</span></a>. Both rounds will be <strong>rated</strong>. You will be given <strong>2 hours and 30 minutes</strong> to solve <strong>7 problems</strong>.</p><h2><strong>Note the unusual time of the round</strong>.</h2><p>The problems are written by <a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-red\" href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\">Pyqe</a>, and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a>.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-legendary\" href=\"/profile/KAN\" title=\"Legendary Grandmaster KAN\"><span class=\"legendary-user-first-letter\">K</span>AN</a> for helping to host the round;</li> <li><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> and <a class=\"rated-user user-orange\" href=\"/profile/ScarletS\" title=\"Master ScarletS\">ScarletS</a> for the based coordination;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/gansixeneh\" title=\"Candidate Master gansixeneh\">gansixeneh</a> and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a> for helping with the problem preparation;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-blue\" href=\"/profile/CyberSleeper\" title=\"Expert CyberSleeper\">CyberSleeper</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Edbert.H\" title=\"Expert Edbert.H\">Edbert.H</a> for providing alternate solutions in the early stages;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for writing the Russian translations;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Aaeria\" title=\"Master Aaeria\">Aaeria</a>, <a class=\"rated-user user-blue\" href=\"/profile/AMnu\" title=\"Expert AMnu\">AMnu</a>, <a class=\"rated-user user-orange\" href=\"/profile/Berted\" title=\"Master Berted\">Berted</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-cyan\" href=\"/profile/buffering\" title=\"Specialist buffering\">buffering</a>, <a class=\"rated-user user-orange\" href=\"/profile/Drew_\" title=\"Master Drew_\">Drew_</a>, <a class=\"rated-user user-legendary\" href=\"/profile/dorijanlendvaj\" title=\"Legendary Grandmaster dorijanlendvaj\"><span class=\"legendary-user-first-letter\">d</span>orijanlendvaj</a>, <a class=\"rated-user user-orange\" href=\"/profile/eggag32\" title=\"Master eggag32\">eggag32</a>, <a class=\"rated-user user-violet\" href=\"/profile/Elben85\" title=\"Candidate Master Elben85\">Elben85</a>, <a class=\"rated-user user-red\" href=\"/profile/emorgan5289\" title=\"International Grandmaster emorgan5289\">emorgan5289</a>, <a class=\"rated-user user-orange\" href=\"/profile/faustaadp\" title=\"Master faustaadp\">faustaadp</a>, <a class=\"rated-user user-red\" href=\"/profile/ffao\" title=\"International Grandmaster ffao\">ffao</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-legendary\" href=\"/profile/gamegame\" title=\"Legendary Grandmaster gamegame\"><span class=\"legendary-user-first-letter\">g</span>amegame</a>, <a class=\"rated-user user-violet\" href=\"/profile/hocky\" title=\"Candidate Master hocky\">hocky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Insta-x\" title=\"Expert Insta-x\">Insta-x</a>, <a class=\"rated-user user-red\" href=\"/profile/jdurie\" title=\"Grandmaster jdurie\">jdurie</a>, <a class=\"rated-user user-orange\" href=\"/profile/joelgun14\" title=\"Master joelgun14\">joelgun14</a>, <a class=\"rated-user user-violet\" href=\"/profile/KerakTelor\" title=\"Candidate Master KerakTelor\">KerakTelor</a>, <a class=\"rated-user user-blue\" href=\"/profile/Marky\" title=\"Expert Marky\">Marky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Murinh0\" title=\"Expert Murinh0\">Murinh0</a>, <a class=\"rated-user user-red\" href=\"/profile/nvmdava\" title=\"Grandmaster nvmdava\">nvmdava</a>, <a class=\"rated-user user-orange\" href=\"/profile/nyab\" title=\"Master nyab\">nyab</a>, <a class=\"rated-user user-orange\" href=\"/profile/Owmicron\" title=\"Master Owmicron\">Owmicron</a>, <a class=\"rated-user user-red\" href=\"/profile/prvocislo\" title=\"Grandmaster prvocislo\">prvocislo</a>, <a class=\"rated-user user-red\" href=\"/profile/PurpleCrayon\" title=\"International Grandmaster PurpleCrayon\">PurpleCrayon</a>, <a class=\"rated-user user-red\" href=\"/profile/rama_pang\" title=\"Grandmaster rama_pang\">rama_pang</a>, <a class=\"rated-user user-blue\" href=\"/profile/TakeMe\" title=\"Expert TakeMe\">TakeMe</a>, <a class=\"rated-user user-blue\" href=\"/profile/sahil_k\" title=\"Expert sahil_k\">sahil_k</a>, <a class=\"rated-user user-red\" href=\"/profile/user202729_\" title=\"International Grandmaster user202729_\">user202729_</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-green\" href=\"/profile/WHCPP\" title=\"Pupil WHCPP\">WHCPP</a>, and <a class=\"rated-user user-violet\" href=\"/profile/ZeroScar\" title=\"Candidate Master ZeroScar\">ZeroScar</a> for testing the contest and providing us very useful feedback;</li> <li>Universitas Indonesia, all the local committees, administrators, and managers of the whole COMPFEST event;</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Codeforces and Polygon platform!</li> </ul><p>COMPFEST itself is an annual event hosted by Universitas Indonesia. It is the largest student-run IT event in Indonesia and competitive programming contest is one of the competitions hosted.</p><p>We hope you will enjoy and have fun in the contest. Muga-muga beja lan isa entuk biji apik!! ๐ช๐ช๐ฅ๐ฅ</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121025\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1876\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1877\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final 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of complaintReasons) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", complaintReason.id);\n $li.find(\"span\")\n .html(getLocalizedName(complaintReason)\n + \" <i class=\\\"icon-question-sign clickable-title\\\" title=\\\"\"\n + getLocalizedDescription(complaintReason)\n + \"\\\"></i>\")\n .attr(\"title\", getLocalizedDescription(complaintReason));\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n if (complaint && complaint.complaintReasonId === complaintReason.id) {\n $li.find(\"input[name=complaintReasonId]\").attr(\"checked\", \"checked\");\n }\n $li.find(\".clickable-title\").click(function () {\n alert(getLocalizedDescription(complaintReason));\n return false;\n }).css(\"position\", \"relative\").css(\"bottom\", \"1px\").css(\"font-size\", \"12px\");\n }\n\n if (complaint) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", 0);\n $li.find(\"span\").html(\"Delete complaint\");\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n }\n\n $popup.find(\"._ComplaintFrame_submitForm\").submit(function () {\n const complaintReasonId = $popup.find(\"input[name=complaintReasonId]:checked\").val();\n if (complaintReasonId === undefined) {\n alert(\"Please select complaint reason\");\n return false;\n }\n\n $.post(\"/data/complaint\", {\n action: \"newComplaint\",\n targetClass: targetClass,\n targetId: targetId,\n complaintReasonId: complaintReasonId\n }, function (response) {\n if (response.success === \"true\") {\n Codeforces.showMessage(\"Complaint has been created\");\n $.facebox.close();\n }\n }, \"json\");\n\n return false;\n });\n }\n }, \"json\");\n\n return false;\n });\n}); </script>\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Pyqe\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Pyqe\">\n Pyqe\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121025#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121025#comments\">\n 41\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121739\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/121114\"> <p>Codeforces Command Lines (2023-10-06)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\" class=\"rated-user user-blue\">Vladosiya</a>,\r\n <a href=\"/topic/121739/en7\">history</a>,\r\n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>We've compiled a list of command lines that Codeforces uses to compile and run solutions in various languages and compilers.</p><p>It is up-to-date as of today (2023-10-06), and we will make efforts to keep it current in the future, but this is not guaranteed.</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121114\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-73866-121739\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"73866\",\n blogEntryId: \"121114\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compilers\" class=\"tag notice\" style=\"text-decoration: none;\">compilers</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compiler+options\" class=\"tag notice\" style=\"text-decoration: none;\">compiler options</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=languages\" class=\"tag notice\" style=\"text-decoration: none;\">languages</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+235</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n <div style=\"position: relative; float: left; left: -1.5rem; top: 1rem;\">\r\n\n\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Vladosiya\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Vladosiya\">\n Vladosiya\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121114#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121114#comments\">\n 8\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121449\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120824\"> <p>Codeforces Round 901 (Div. 1, Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a>,\r\n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I'm pleased to invite you to <a href=\"/contest/1874\" title=\"Codeforces Round 901 (Div. 1)\">Codeforces Round 901 (Div. 1)</a> and <a href=\"/contest/1875\" title=\"Codeforces Round 901 (Div. 2)\">Codeforces Round 901 (Div. 2)</a>. It starts on <a class=\"contest-time\" contestid=\"1874\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=30&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/30/2023 17:35 (Moscow time)</span></a>. It also means, the National Day of China arrives during the round. Wish you a nice vacation! ๐๐๐</p><p>For both divisions, you will have <strong>3 hours</strong> to solve <strong>7 problems</strong>.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his wonderful coordination.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for Russian translation and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for helping us with Russian clarifications.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\">GeZhiyuan</a> for providing all the problems and "a few" rejected problems.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> and <a class=\"rated-user user-red\" href=\"/profile/SanweiTreap\" title=\"Grandmaster SanweiTreap\">SanweiTreap</a> for helping me prepare the problems.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a>, <a class=\"rated-user user-legendary\" href=\"/profile/wangziji\" title=\"Legendary Grandmaster wangziji\"><span class=\"legendary-user-first-letter\">w</span>angziji</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> and <a class=\"rated-user user-legendary\" href=\"/profile/flowerletter\" title=\"Legendary Grandmaster flowerletter\"><span class=\"legendary-user-first-letter\">f</span>lowerletter</a> for Legendary Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/sjcsjcsjc\" title=\"International Grandmaster sjcsjcsjc\">sjcsjcsjc</a>, <a class=\"rated-user user-red\" href=\"/profile/He_Ren\" title=\"International Grandmaster He_Ren\">He_Ren</a>, <a class=\"rated-user user-red\" href=\"/profile/GaryZ005\" title=\"International Grandmaster GaryZ005\">GaryZ005</a>, <a class=\"rated-user user-red\" href=\"/profile/platelet\" title=\"International Grandmaster platelet\">platelet</a>, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a>, <a class=\"rated-user user-red\" href=\"/profile/thenymphsofdelphi\" title=\"International Grandmaster thenymphsofdelphi\">thenymphsofdelphi</a>, <a class=\"rated-user user-red\" href=\"/profile/DerekFeng\" title=\"International Grandmaster DerekFeng\">DerekFeng</a>, <a class=\"rated-user user-red\" href=\"/profile/Juanzhang\" title=\"International Grandmaster Juanzhang\">Juanzhang</a> and <a class=\"rated-user user-red\" href=\"/profile/ttklwxx\" title=\"International Grandmaster ttklwxx\">ttklwxx</a> for International Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/juju527\" title=\"Grandmaster juju527\">juju527</a>, <a class=\"rated-user user-red\" href=\"/profile/zimpha\" title=\"Grandmaster zimpha\">zimpha</a>, <a class=\"rated-user user-red\" href=\"/profile/765\" title=\"Grandmaster 765\">765</a>, <a class=\"rated-user user-red\" href=\"/profile/xuanquang1999\" title=\"Grandmaster xuanquang1999\">xuanquang1999</a>, <a class=\"rated-user user-red\" href=\"/profile/CrTsIr\" title=\"Grandmaster CrTsIr\">CrTsIr</a> and <a class=\"rated-user user-red\" href=\"/profile/EasonTAO\" title=\"Grandmaster EasonTAO\">EasonTAO</a> for Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/SATSKY\" title=\"Master SATSKY\">SATSKY</a>, <a class=\"rated-user user-orange\" href=\"/profile/lanhf\" title=\"Master lanhf\">lanhf</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hank2019\" title=\"Master Hank2019\">Hank2019</a> and <a class=\"rated-user user-orange\" href=\"/profile/Yakumo_Ran\" title=\"Master Yakumo_Ran\">Yakumo_Ran</a> for Master Testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/DaniraSilla\" title=\"Candidate Master DaniraSilla\">DaniraSilla</a> and <a class=\"rated-user user-violet\" href=\"/profile/kriepiekrollie\" title=\"Candidate Master kriepiekrollie\">kriepiekrollie</a> for Candidate Master Testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/raulandreipop\" title=\"Expert raulandreipop\">raulandreipop</a>, <a class=\"rated-user user-blue\" href=\"/profile/micho\" title=\"Expert micho\">micho</a>, <a class=\"rated-user user-blue\" href=\"/profile/alwyn\" title=\"Expert alwyn\">alwyn</a>, <a class=\"rated-user user-blue\" href=\"/profile/ArgintLaAnu\" title=\"Expert ArgintLaAnu\">ArgintLaAnu</a>, <a class=\"rated-user user-blue\" href=\"/profile/IssamOtoz\" title=\"Expert IssamOtoz\">IssamOtoz</a> and <a class=\"rated-user user-blue\" href=\"/profile/jakao\" title=\"Expert jakao\">jakao</a> for Expert Testing.</p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/CLown1331\" title=\"Pupil CLown1331\">CLown1331</a> for Pupil Testing.</p></li> <li><p>You for participating the round.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</p></li> </ul><p>Especially, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his great contribution to the round, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a> for providing user solutions for all the problems, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> for making the announcement and tutorial more readable.</p><p>Finally and most importantly, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> for helping me with everything patiently all the time. This round can't happen without him.</p><p>The main character of the problems will be Jellyfish, a sweet little girl. ๐๐๐</p><p>Score distribution:</p> <ul> <li><p>Div.1: $$$500$$$ โ $$$1250$$$ โ $$$1500$$$ โ $$$2250$$$ โ $$$3000$$$ โ $$$4000$$$ โ $$$5000$$$</p></li> <li><p>Div.2: $$$500$$$ โ $$$1000$$$ โ $$$1000$$$ โ $$$1250$$$ โ $$$2000$$$ โ $$$2250$$$ โ $$$3000$$$</p></li> </ul><p>Good Luck & Have Fun! ๐ฅ๐ฅ๐ฅ</p><p><strong>UPD1:</strong> <a href=\"https://codeforces.com/blog/entry/120943\">Editorial</a> is out.</p><p><strong>UPD2:</strong> Congratulations to the winners!</p> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\"><span class=\"legendary-user-first-letter\">B</span>enq</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Qingyu\" title=\"International Grandmaster Qingyu\">Qingyu</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/amiya\" title=\"Legendary Grandmaster amiya\"><span class=\"legendary-user-first-letter\">a</span>miya</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/RollingPanda\" title=\"Newbie RollingPanda\">RollingPanda</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/WanYuanShenWanDe\" title=\"Newbie WanYuanShenWanDe\">WanYuanShenWanDe</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-red\" href=\"/profile/H_stove\" title=\"Grandmaster H_stove\">H_stove</a></p><p>B. <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>C. <a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></p><p>D. <a class=\"rated-user user-red\" href=\"/profile/ooOAM\" title=\"Grandmaster ooOAM\">ooOAM</a></p><p>E. <a class=\"rated-user user-orange\" href=\"/profile/Salley-Garden\" title=\"Master Salley-Garden\">Salley-Garden</a></p><p>F. <a class=\"rated-user user-red\" href=\"/profile/i_will_be_less_than_blue\" title=\"Grandmaster i_will_be_less_than_blue\">i_will_be_less_than_blue</a></p><p>G. <a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a> (after the contest)</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-blue\" href=\"/profile/Azaml\" title=\"Expert Azaml\">Azaml</a></p><p>B. <a class=\"rated-user user-blue\" href=\"/profile/Shirotsume\" title=\"Expert Shirotsume\">Shirotsume</a></p><p>C. <a class=\"rated-user user-gray\" href=\"/profile/viveksingh912\" title=\"Newbie viveksingh912\">viveksingh912</a></p><p>D. <a class=\"rated-user user-gray\" href=\"/profile/kaiboy\" title=\"Newbie kaiboy\">kaiboy</a></p><p>E. <a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p><p>F. <a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p><p>G. <a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></div></div></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120824\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1874\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1875\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-238039-121449\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"238039\",\n blogEntryId: \"120824\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+165</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/GeZhiyuan\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/GeZhiyuan\">\n GeZhiyuan\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120824#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120824#comments\">\n 231\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121303\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120678\"> <p>Codeforces Round #900 (Div. 3)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AlphaMale06\" title=\"Specialist AlphaMale06\" class=\"rated-user user-cyan\">AlphaMale06</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p><a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a> and I are glad to invite you to the <a href=\"/contest/1878\" title=\"Codeforces Round 900 (Div. 3)\">Codeforces Round 900 (Div. 3)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1878\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=26&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/26/2023 17:35 (Moscow time)</span></a></p><p>You will be given <strong>7 problems</strong> and <strong>2 hours and 15 minutes</strong> to solve them.</p><p>Note that the <strong>penalty</strong> for the wrong submission in this round is <strong>10 minutes</strong>.</p><p>Also note that there will be a <strong>12 hour open hacking phase</strong> after the round.</p><p><a href=\"https://codeforces.com/blog/entry/59228\">Remember</a>, that only the <em>trusted participants of the third division</em> will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a <em>trusted participant of the third division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them)</li> <li>do not have a point of 1900 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, the round will be rated for you.</strong></p><p>Problems have been created and prepared by <a class=\"rated-user user-blue\" href=\"/profile/AlphaMale06\" title=\"Expert AlphaMale06\">AlphaMale06</a>, <a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>.</p><p>We would also to thank:</p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for the amazing coordination and help with preparing a balanced problemset, and for giving us the opportunity to create a Div. 3 round.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Polygon and Codeforces platforms.</li> <li><a class=\"rated-user user-red\" href=\"/profile/JovanB\" title=\"Grandmaster JovanB\">JovanB</a>, <a class=\"rated-user user-red\" href=\"/profile/abc864197532\" title=\"International Grandmaster abc864197532\">abc864197532</a>, <a class=\"rated-user user-red\" href=\"/profile/sevlll777\" title=\"Grandmaster sevlll777\">sevlll777</a> for red testing</li> <li><a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>, <a class=\"rated-user user-orange\" href=\"/profile/n0sk1ll\" title=\"Master n0sk1ll\">n0sk1ll</a>, <a class=\"rated-user user-orange\" href=\"/profile/allllekssssa\" title=\"Master allllekssssa\">allllekssssa</a>, <a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a>, <a class=\"rated-user user-orange\" href=\"/profile/misorin\" title=\"International Master misorin\">misorin</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hyperbolic\" title=\"International Master Hyperbolic\">Hyperbolic</a> for yellow testing</li> <li><a class=\"rated-user user-violet\" href=\"/profile/DAleksa\" title=\"Candidate Master DAleksa\">DAleksa</a>, <a class=\"rated-user user-violet\" href=\"/profile/ljuba\" title=\"Candidate Master ljuba\">ljuba</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex.kudryashov\" title=\"Candidate Master alex.kudryashov\">alex.kudryashov</a> for purple testing</li> <li><a class=\"rated-user user-blue\" href=\"/profile/MihailoT\" title=\"Expert MihailoT\">MihailoT</a>, <a class=\"rated-user user-blue\" href=\"/profile/SashaT9\" title=\"Expert SashaT9\">SashaT9</a>, <a class=\"rated-user user-blue\" href=\"/profile/ELDRVD\" title=\"Expert ELDRVD\">ELDRVD</a>, <a class=\"rated-user user-blue\" href=\"/profile/Chrisedyong\" title=\"Expert Chrisedyong\">Chrisedyong</a>, <a class=\"rated-user user-blue\" href=\"/profile/tryptophan\" title=\"Expert tryptophan\">tryptophan</a> for blue testing</li> <li><a class=\"rated-user user-cyan\" href=\"/profile/Andrijanikolic73\" title=\"Specialist Andrijanikolic73\">Andrijanikolic73</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Mihajlo18\" title=\"Specialist Mihajlo18\">Mihajlo18</a>, <a class=\"rated-user user-cyan\" href=\"/profile/UrosNedic\" title=\"Specialist UrosNedic\">UrosNedic</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Klaus26\" title=\"Specialist Klaus26\">Klaus26</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Escaquejant\" title=\"Specialist Escaquejant\">Escaquejant</a>, <a class=\"rated-user user-cyan\" href=\"/profile/smax294\" title=\"Specialist smax294\">smax294</a>, <a class=\"rated-user user-cyan\" href=\"/profile/max0n\" title=\"Specialist max0n\">max0n</a> for cyan testing</li> <li><a class=\"rated-user user-gray\" href=\"/profile/Budimmm\" title=\"Newbie Budimmm\">Budimmm</a> for gray testing</li> </ol><p>Also a very special thanks to the most dedicated tester I have ever seen, <a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>.</p><p>I wish you luck, and hope you like the problems and learn from them.</p><p>Update: <a href=\"https://codeforces.com/blog/entry/120813\">Editorial</a> is out.</p><p>Congratulations to the winners:</p><p>Unofficial:</p> <ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/SSerxhs\" title=\"International Grandmaster SSerxhs\">SSerxhs</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/neal\" title=\"Legendary Grandmaster neal\"><span class=\"legendary-user-first-letter\">n</span>eal</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/risujiroh\" title=\"International Grandmaster risujiroh\">risujiroh</a></p></li> </ol><p>Official:</p> <ol> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/hackerjohn\" title=\"Specialist hackerjohn\">hackerjohn</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/wahb\" title=\"Specialist wahb\">wahb</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/kutcoder\" title=\"Specialist kutcoder\">kutcoder</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Sxy_Limit\" title=\"Specialist Sxy_Limit\">Sxy_Limit</a></p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/not_rainboy\" title=\"Pupil not_rainboy\">not_rainboy</a></p></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120678\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1878\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 900 (Div. 3)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-269459-121303\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"269459\",\n blogEntryId: \"120678\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+192</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AlphaMale06\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AlphaMale06\">\n AlphaMale06\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120678#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120678#comments\">\n 347\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121269\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120644\"> <p>Codeforces Round 899 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a>,\r\n <a href=\"/topic/121269/en9\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I am pleased to invite you to participate in <a href=\"/contest/1882\" title=\"Codeforces Round 899 (Div. 2)\">Codeforces Round 899 (Div. 2)</a>, which will be held on <a class=\"contest-time\" contestid=\"1882\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=25&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/25/2023 17:35 (Moscow time)</span></a>.</p><p>All problems were written and prepared by me.</p><p>You will be given <strong>5 problems, and one of them is divided into two subtasks</strong>. You will have <strong>2 hours</strong> to solve them.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-orange\" href=\"/profile/irkstepanov\" title=\"International Master irkstepanov\">irkstepanov</a> for excellent coordination and Russian translation!</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for providing useful feedbacks.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a> for helping me much with one problem of the contest.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/ko_osaga\" title=\"Legendary Grandmaster ko_osaga\"><span class=\"legendary-user-first-letter\">k</span>o_osaga</a> for Nutella testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/leinad2\" title=\"Grandmaster leinad2\">leinad2</a>, <a class=\"rated-user user-red\" href=\"/profile/Numbering\" title=\"Grandmaster Numbering\">Numbering</a>, <a class=\"rated-user user-red\" href=\"/profile/qwerasdfzxcl\" title=\"International Grandmaster qwerasdfzxcl\">qwerasdfzxcl</a>, <a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a>, <a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for Red testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Kaling\" title=\"Master Kaling\">Kaling</a>, <a class=\"rated-user user-orange\" href=\"/profile/Mingyu331\" title=\"Master Mingyu331\">Mingyu331</a>, <a class=\"rated-user user-orange\" href=\"/profile/chaeyihwan\" title=\"International Master chaeyihwan\">chaeyihwan</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kawaii2DIdolOfGSHS\" title=\"International Master Kawaii2DIdolOfGSHS\">Kawaii2DIdolOfGSHS</a>, <a class=\"rated-user user-orange\" href=\"/profile/azberjibiou\" title=\"International Master azberjibiou\">azberjibiou</a>, <a class=\"rated-user user-orange\" href=\"/profile/mjhmjh1104\" title=\"Master mjhmjh1104\">mjhmjh1104</a>, <a class=\"rated-user user-orange\" href=\"/profile/DELTARUNE\" title=\"Master DELTARUNE\">DELTARUNE</a>, <a class=\"rated-user user-orange\" href=\"/profile/wuhudsm\" title=\"Master wuhudsm\">wuhudsm</a>, <a class=\"rated-user user-orange\" href=\"/profile/hypergraph_coloring\" title=\"International Master hypergraph_coloring\">hypergraph_coloring</a> for Orange testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/unordered_map\" title=\"Candidate Master unordered_map\">unordered_map</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex0211\" title=\"Candidate Master alex0211\">alex0211</a>, <a class=\"rated-user user-violet\" href=\"/profile/gs20036\" title=\"Candidate Master gs20036\">gs20036</a>, <a class=\"rated-user user-violet\" href=\"/profile/namolbbaemi\" title=\"Candidate Master namolbbaemi\">namolbbaemi</a>, <a class=\"rated-user user-violet\" href=\"/profile/eeeDA\" title=\"Candidate Master eeeDA\">eeeDA</a>, <a class=\"rated-user user-violet\" href=\"/profile/nlog\" title=\"Candidate Master nlog\">nlog</a> for Purple testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/andyandy\" title=\"Expert andyandy\">andyandy</a>, <a class=\"rated-user user-blue\" href=\"/profile/JaewonOh\" title=\"Expert JaewonOh\">JaewonOh</a>, <a class=\"rated-user user-blue\" href=\"/profile/KongUm\" title=\"Expert KongUm\">KongUm</a>, <a class=\"rated-user user-blue\" href=\"/profile/Coruncanius\" title=\"Expert Coruncanius\">Coruncanius</a>, <a class=\"rated-user user-blue\" href=\"/profile/ez_code\" title=\"Expert ez_code\">ez_code</a>, <a class=\"rated-user user-blue\" href=\"/profile/fs_edge\" title=\"Expert fs_edge\">fs_edge</a>, <a class=\"rated-user user-blue\" href=\"/profile/chromate00\" title=\"Expert chromate00\">chromate00</a> for Blue testing.</p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/Hanlana18\" title=\"Newbie Hanlana18\">Hanlana18</a>, <a class=\"rated-user user-gray\" href=\"/profile/papergundam\" title=\"Newbie papergundam\">papergundam</a>, <a class=\"rated-user user-gray\" href=\"/profile/sjmjys954646\" title=\"Newbie sjmjys954646\">sjmjys954646</a> for Gray testing.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for great Polygon and Codeforces platforms!</p></li> <li><p>And last but not least, <a class=\"rated-user user-legendary\" href=\"https://codeforces.com/profile/\">You</a> for participating in the round!</p></li> </ul><p>Score distribution: $$$500 - 1000 - 1500 - 2000 - (2000 + 2000)$$$</p><p>Good luck and enjoy the round!</p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120792\">Editorial</a> is out. </p><p><strong>UPD2</strong>: Congratulations to the winners!</p><p><strong>Official Contestants</strong></p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Lycorisqwq\" title=\"Expert Lycorisqwq\">Lycorisqwq</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/zepto\" title=\"Unrated, zepto\">zepto</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/vjudge39\" title=\"Unrated, vjudge39\">vjudge39</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/Beelzebub_blue\" title=\"Candidate Master Beelzebub_blue\">Beelzebub_blue</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/_t_W_\" title=\"Candidate Master _t_W_\">_t_W_</a></li> </ol><p><strong>Official + Unofficial Contestants</strong></p> <ol> <li><a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/antontrygubO_o\" title=\"International Grandmaster antontrygubO_o\">antontrygubO_o</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a></li> <li><a class=\"rated-user user-orange\" href=\"/profile/KumaTachiRen\" title=\"Master KumaTachiRen\">KumaTachiRen</a></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120644\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1882\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 899 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-272374-121269\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"272374\",\n blogEntryId: \"120644\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+524</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/windva\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/windva\">\n windva\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120644#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120644#comments\">\n 188\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121316\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120691\"> <p>Educational Codeforces Round 155 [Rated for Div. 2]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a>,\r\n <a href=\"/topic/121316/en5\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p>On <a class=\"contest-time\" contestid=\"1879\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=24&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/24/2023 17:35 (Moscow time)</span></a> <a href=\"/contest/1879\" title=\"Educational Codeforces Round 155 (Rated for Div. 2)\">Educational Codeforces Round 155 (Rated for Div. 2)</a> will start.</p><p>Series of Educational Rounds continue being held as <a href=\"https://harbour.space/\">Harbour.Space University</a> initiative! You can read the details about the cooperation between <a href=\"https://harbour.space/\">Harbour.Space University</a> and Codeforces in the <a href=\"https://mirror.codeforces.com/blog/entry/51208\">blog post</a>.</p><p>This round will be <strong>rated for the participants with rating lower than 2100</strong>. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.</p><p>You will be given <strong>6 or 7 problems</strong> and <strong>2 hours</strong> to solve them.</p><p>The problems were invented and prepared by Adilbek <a class=\"rated-user user-orange\" href=\"/profile/adedalic\" title=\"International Master adedalic\">adedalic</a> Dalabaev, Ivan <a class=\"rated-user user-red\" href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\">BledDest</a> Androsov, Maksim <a class=\"rated-user user-violet\" href=\"/profile/Neon\" title=\"Candidate Master Neon\">Neon</a> Mescheryakov, Roman <a class=\"rated-user user-orange\" href=\"/profile/Roms\" title=\"Master Roms\">Roms</a> Glazov and me. Also, huge thanks to Mike <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> Mirzayanov for great systems Polygon and Codeforces.</p><p>Good luck to all the participants!</p><p>Our friends at Harbour.Space also have a message for you:</p> <center><img alt=\"Harbour.Space\" src=\"/predownloaded/29/a4/29a4884273346021dec6559e9785af37a662cc56.png\" style=\"height: 200.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></center> <center style=\"margin: 1.0em;\"><b>FULLY FUNDED SCHOLARSHIPS for Masters in Data Science and Computer Science </b></center><p><em>Scholarships for Master's students in <a href=\"https://harbour.space/computer-science\">Computer Science</a> and <a href=\"https://harbour.space/data-science\">Data Science</a> are available in <a href=\"https://harbour.space\">Harbour.Space University</a> Barcelona campus!</em> </p><p><strong>Scholarship Summary:</strong></p> <ul> <li><em>Fully funded scholarship (29.900 โฌ/year) to study a Masterโs degree in Data Science or Computer Science for two years</em></li> <li><em>Successful applicants will become part of the Universityโs โTalent poolโ and will be shown to the sponsoring companies. In case the candidate is picked for the Work&Study Program from our industry partner, the student starts an internship with a commitment to study 3 hours/day and work for 4 hour/day</em></li> </ul><p><em>Please note preselected candidates will be requested to pay a non-refundable application fee of 85โฌ to study at Harbour.Space University.</em></p><p><em><strong>Candidateโs commitment:</strong></em></p><p><em>You will complete 15 modules (each three weeks long) in one year. The daily class workload is 3 hours, plus homework to complete in your own time.</em></p><p><em><strong>Candidateโs requirements:</strong></em> </p> <ul> <li><em>Bachelor's degree in the field of Mathematics, Statistics, Data Science, Computer Science or similar</em></li> <li><em>English proficiency</em></li> <li><em>Advanced knowledge and experience in Python, SQL, Spark/Scala, and bash</em></li> <li><em>Experienced use of Big Data technologies: Spark, HDFS, Kafka, etc.</em></li> <li><em>Hands-on experience with Data Science techniques: feature engineering,</em></li> <li><em>Strong ML knowledge</em></li> <li><em>Strong Software Engineering Background</em></li> <li><em>Problem-solving aptitude</em></li> </ul> <center style=\"margin: 2.5em;\"> <a href=\"https://harbour.space/account/apply-process?utm_source=codeforces&utm_medium=partner&utm_campaign=bcn_b2b\" style=\"text-decoration: none;font-size: 14.0px;background-color: rgb(98,91,183);color: white;font-weight: bold;padding: 0.5em 1.0em;\">Apply here โ</a> </center><p><strong>UPD:</strong> <a href=\"https://codeforces.com/blog/entry/120773\">Editorial is out</a> </p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120691\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1879\" class=\"notice\" style=\"text-decoration: none;\">Educational Codeforces Round 155 (Rated for Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-42750-121316\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"42750\",\n blogEntryId: \"120691\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+245</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/awoo\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/awoo\">\n awoo\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120691#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120691#comments\">\n 189\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121227\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120602\"> <p>Codeforces Round 898 (Div. 4)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/mesanu\" title=\"Candidate Master mesanu\" class=\"rated-user user-violet\">mesanu</a>,\r\n <a href=\"/topic/121227/en2\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p><a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and I want to invite you to <a href=\"/contest/1873\" title=\"Codeforces Round 898 (Div. 4)\">Codeforces Round 898 (Div. 4)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1873\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=21&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/21/2023 17:35 (Moscow time)</span></a>.</p><p>The format of the event will be identical to Div. 3 rounds:</p> <ul> <li>5-8 tasks;</li> <li>ICPC rules with a penalty of 10 minutes for an incorrect submission;</li> <li>12-hour phase of open hacks after the end of the round (hacks do not give additional points)</li> <li>after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated</li> <li>by default, only "trusted" participants are shown in the results table (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).</li> </ul><p>We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.</p><p>Only <em>trusted participants of the fourth division</em> will be included in the official standings table. This is a forced measure for combating unsporting behaviour. To qualify as <em>a trusted participant of the fourth division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them),</li> <li>do not have a point of 1400 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), then the round will be rated for you.</strong></p><p>Many thanks to the testers: <a class=\"rated-user user-orange\" href=\"/profile/Gheal\" title=\"Master Gheal\">Gheal</a>, <a class=\"rated-user user-orange\" href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\">Phantom_Performer</a>, <a class=\"rated-user user-orange\" href=\"/profile/KrowSavcik\" title=\"Master KrowSavcik\">KrowSavcik</a>, <a class=\"rated-user user-cyan\" href=\"/profile/haochenkang\" title=\"Specialist haochenkang\">haochenkang</a>, <a class=\"rated-user user-cyan\" href=\"/profile/sandry24\" title=\"Specialist sandry24\">sandry24</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>, <a class=\"rated-user user-violet\" href=\"/profile/NintsiChkhaidze\" title=\"Candidate Master NintsiChkhaidze\">NintsiChkhaidze</a>, <a class=\"rated-user user-orange\" href=\"/profile/erekle\" title=\"International Master erekle\">erekle</a>, <a class=\"rated-user user-red\" href=\"/profile/Dominater069\" title=\"Grandmaster Dominater069\">Dominater069</a>, <a class=\"rated-user user-blue\" href=\"/profile/MADE_IN_HEAVEN\" title=\"Expert MADE_IN_HEAVEN\">MADE_IN_HEAVEN</a>, <a class=\"rated-user user-blue\" href=\"/profile/Qualified\" title=\"Expert Qualified\">Qualified</a>.</p><p>We suggest reading all of the problems and hope you will find them interesting!</p><p><strong>Good Luck!</strong></p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120634\">Editorial is out!</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120602\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1873\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 898 (Div. 4)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-188642-121227\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"188642\",\n blogEntryId: \"120602\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+200</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/mesanu\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/mesanu\">\n mesanu\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120602#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120602#comments\">\n 179\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121083\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120458\"> <p>CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/glebustim\" title=\"Grandmaster glebustim\" class=\"rated-user user-red\">glebustim</a>,\r\n <a href=\"/topic/121083/en8\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3>Hello, Codeforces!</h3><p><a class=\"rated-user user-red\" href=\"/profile/SomethingNew\" title=\"International Grandmaster SomethingNew\">SomethingNew</a> and I are glad to invite you to <a href=\"/contest/1870\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a>, which will take place on <a class=\"contest-time\" contestid=\"1870\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=18&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/18/2023 17:35 (Moscow time)</span></a>. You will have 2 hours 15 minutes to solve 8 problems. The round will be rated for everyone.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-orange\" href=\"/profile/74TrAkToR\" title=\"International Master 74TrAkToR\">74TrAkToR</a> for coordinating this round.</li> <li><a class=\"rated-user user-legendary\" href=\"/profile/isaf27\" title=\"Legendary Grandmaster isaf27\"><span class=\"legendary-user-first-letter\">i</span>saf27</a>, <a class=\"rated-user user-legendary\" href=\"/profile/ugly2333\" title=\"Legendary Grandmaster ugly2333\"><span class=\"legendary-user-first-letter\">u</span>gly2333</a>, <a class=\"rated-user user-red\" href=\"/profile/DataStructures\" title=\"Grandmaster DataStructures\">DataStructures</a>, <a class=\"rated-user user-red\" href=\"/profile/Little09\" title=\"International Grandmaster Little09\">Little09</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kieray\" title=\"Master Kieray\">Kieray</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-orange\" href=\"/profile/Dart-Xeyter\" title=\"International Master Dart-Xeyter\">Dart-Xeyter</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/meowcneil\" title=\"Master meowcneil\">meowcneil</a>, <a class=\"rated-user user-orange\" href=\"/profile/127.0.0.1\" title=\"Master 127.0.0.1\">127.0.0.1</a>, <a class=\"rated-user user-violet\" href=\"/profile/Nanani\" title=\"Candidate Master Nanani\">Nanani</a>, <a class=\"rated-user user-violet\" href=\"/profile/nnv-nick\" title=\"Candidate Master nnv-nick\">nnv-nick</a>, <a class=\"rated-user user-violet\" href=\"/profile/SomethingDifferent\" title=\"Candidate Master SomethingDifferent\">SomethingDifferent</a>, <a class=\"rated-user user-blue\" href=\"/profile/vl342\" title=\"Expert vl342\">vl342</a>, <a class=\"rated-user user-blue\" href=\"/profile/shiv_codegen\" title=\"Expert shiv_codegen\">shiv_codegen</a>, <a class=\"rated-user user-cyan\" href=\"/profile/M1lkas\" title=\"Specialist M1lkas\">M1lkas</a>, <a class=\"rated-user user-green\" href=\"/profile/allmath\" title=\"Pupil allmath\">allmath</a>, <a class=\"rated-user user-gray\" href=\"/profile/sdyakonov\" title=\"Newbie sdyakonov\">sdyakonov</a> for testing the round and providing useful feedback.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</li> </ul><h4><strong>Score distribution:</strong></h4><p>500 โ 750 โ 1500 โ 1750 โ 2750 โ 3250 โ 3250 โ 4000</p><p>We hope that our problems will be interesting for you!</p><h4><a href=\"https://codeforces.com/blog/entry/120524\">Editorial</a></h4><p><strong>Congratulations to the winners!</strong></p> <ol> <li><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/emptyhope\" title=\"Legendary Grandmaster emptyhope\"><span class=\"legendary-user-first-letter\">e</span>mptyhope</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/maspy\" title=\"International Grandmaster maspy\">maspy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/AoLiGei\" title=\"Legendary Grandmaster AoLiGei\"><span class=\"legendary-user-first-letter\">A</span>oLiGei</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/noimi\" title=\"Legendary Grandmaster noimi\"><span class=\"legendary-user-first-letter\">n</span>oimi</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></li> </ol><p>And here is the information from our title sponsor:</p><p><img src=\"/predownloaded/ce/9f/ce9f87d5c429f47e7691bef3a8934ebf36af3f15.jpg\" style=\"width: 250.0px;float: right;margin: 0 1.0em 1.0em 1.0em;max-width: 100.0%;max-height: 100.0%;\" /></p><p><em>Hello, Codeforces!</em></p><p><em>We, the <a href=\"https://ton.org/\">TON Foundation</a> team, are pleased to support CodeTON Round 6.</em></p><p><em>The Open Network (TON) is a fully decentralized layer-1 blockchain designed to onboard billions of users to Web3.</em></p><p><em>Since July 2022, <a href=\"/blog/entry/104544\">we have been supporting</a> Codeforces as a title sponsor. This round is another way for us to contribute to the development of the community.</em></p><p><em>The winners of CodeTON Round 6 will receive valuable prizes.</em></p><p><em>The first 1,023 participants will receive prizes in TON cryptocurrency:</em></p> <ul> <li><em>1st place: 1,024 TON</em></li> <li><em>2โ3 places: 512 TON each</em></li> <li><em>4โ7 places: 256 TON each</em></li> <li><em>8โ15 places: 128 TON each</em></li> <li><em>โฆ</em></li> <li><em>512โ1,023 places: 2 TON each</em></li> </ul><p><em>We wish you good luck at CodeTON Round 6 and hope you enjoy the contest!</em></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120458\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1870\" class=\"notice\" style=\"text-decoration: none;\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-223600-121083\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"223600\",\n blogEntryId: \"120458\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+394</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/glebustim\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/glebustim\">\n glebustim\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120458#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120458#comments\">\n 171\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"120865\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120240\"> <p>Codeforces Round #897 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/salyg1n\" title=\"Master salyg1n\" class=\"rated-user user-orange\">salyg1n</a>,\r\n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces! ๐คฏ</p><p><a class=\"rated-user user-red\" href=\"/profile/green_gold_dog\" title=\"Grandmaster green_gold_dog\">green_gold_dog</a>, <a class=\"rated-user user-orange\" href=\"/profile/ace5\" title=\"International Master ace5\">ace5</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> and I <a class=\"rated-user user-orange\" href=\"/profile/salyg1n\" title=\"Master salyg1n\">salyg1n</a> are pleased to invite you to participate in <a href=\"https://codeforces.com/contest/1867\">Codeforces Round 897 (Div. 2)</a>, which will take place on <a href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=11&month=9&year=2023&hour=17&min=35&sec=0&p1=166\">Monday, September 11, 2023 in 17:35</a>.</p><p>This round will be <strong>rated</strong> for participants whose <strong>rating is below 2100</strong>.</p><p>You will be given 6 tasks and 2 hours to solve them. We recommend reading all the tasks. <strong>Interactive tasks may occur in the round</strong>, so we suggest reading this <a href=\"https://codeforces.com/blog/entry/45307\">post</a>.</p><p>We want to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/Aleks5d\" title=\"Grandmaster Aleks5d\">Aleks5d</a> for coordinating the round and improving one of the tasks. ๐ค</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Allvik06\" title=\"International Grandmaster Allvik06\">Allvik06</a>, <a class=\"rated-user user-red\" href=\"/profile/Nutella3000\" title=\"Grandmaster Nutella3000\">Nutella3000</a>, <a class=\"rated-user user-red\" href=\"/profile/arbuzick\" title=\"International Grandmaster arbuzick\">arbuzick</a>, <a class=\"rated-user user-red\" href=\"/profile/alegsandyr\" title=\"Grandmaster alegsandyr\">alegsandyr</a>, <a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/FairyWinx\" title=\"Grandmaster FairyWinx\">FairyWinx</a>, <a class=\"rated-user user-red\" href=\"/profile/zwezdinv\" title=\"Grandmaster zwezdinv\">zwezdinv</a>, <a class=\"rated-user user-orange\" href=\"/profile/valerikk\" title=\"Master valerikk\">valerikk</a>, <a class=\"rated-user user-orange\" href=\"/profile/danya111\" title=\"Master danya111\">danya111</a>, <a class=\"rated-user user-orange\" href=\"/profile/EJIC_B_KEDAX\" title=\"Master EJIC_B_KEDAX\">EJIC_B_KEDAX</a>, <a class=\"rated-user user-orange\" href=\"/profile/dushenkov\" title=\"Master dushenkov\">dushenkov</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/aleksandro\" title=\"Master aleksandro\">aleksandro</a>, <a class=\"rated-user user-orange\" href=\"/profile/Yar_sem\" title=\"Master Yar_sem\">Yar_sem</a>, <a class=\"rated-user user-orange\" href=\"/profile/asafiul\" title=\"Master asafiul\">asafiul</a>, <a class=\"rated-user user-violet\" href=\"/profile/Ivan_len\" title=\"Candidate Master Ivan_len\">Ivan_len</a>, <a class=\"rated-user user-violet\" href=\"/profile/ArtAlex\" title=\"Candidate Master ArtAlex\">ArtAlex</a>, <a class=\"rated-user user-violet\" href=\"/profile/Undying\" title=\"Candidate Master Undying\">Undying</a>, <a class=\"rated-user user-violet\" href=\"/profile/JustNik77\" title=\"Candidate Master JustNik77\">JustNik77</a>, <a class=\"rated-user user-violet\" href=\"/profile/Pavarishko\" title=\"Candidate Master Pavarishko\">Pavarishko</a> and <a class=\"rated-user user-violet\" href=\"/profile/xnor\" title=\"Candidate Master xnor\">xnor</a> for testing the round and giving valuable feedback. ๐ <span style=\"color: rgb(255,255,255);\">orz</span></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/ryskmax\" title=\"Expert ryskmax\">ryskmax</a> for being the only blue tester and giving valuable feedback. ๐ณ </p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/DimaTomsk\" title=\"Master DimaTomsk\">DimaTomsk</a> and <a class=\"rated-user user-orange\" href=\"/profile/ilyakrasnovv\" title=\"Master ilyakrasnovv\">ilyakrasnovv</a> for viewing some of the tasks and giving valuable feedback. ๐ค <span style=\"color: rgb(255,255,255);\"></span></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/stepanov.aa\" title=\"Grandmaster stepanov.aa\">stepanov.aa</a> for <strong>not</strong> testing the round. ๐ฆฅ <span style=\"color: rgb(255,255,255);\">:(</span></p></li> <li><p>The authors of the task <em>5. Overtaking</em> from IOI 2023 for <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> taking a <strong>gold medal</strong>. ๐ฅ <span style=\"color: rgb(255,255,255);\">Too dead? Yes, so am I.</span></p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and <a class=\"rated-user user-admin\" href=\"/profile/geranazavr555\" title=\"Headquarters, geranazavr555\">geranazavr555</a> for the excellent codeforces and polygon platforms. ๐ฆ <span style=\"color: rgb(255,255,255);\">Thank you!</span></p></li> </ul><p>We hope you'll enjoy our problems! Good luck!</p><p><strong>UPD.</strong> Score distribution: $$$500 - 1000 - 1250 - 2000 - (2000 + 1000) - 4000$$$.</p><p><strong>UPD2.</strong> Congratulations to the winners!</p><p><strong>Div. 2</strong></p> <ol> <li><p><a class=\"rated-user user-violet\" href=\"/profile/candidatecandidatemaster\" title=\"Candidate Master candidatecandidatemaster\">candidatecandidatemaster</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Coreopsis\" title=\"Specialist Coreopsis\">Coreopsis</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/iFFT\" title=\"Expert iFFT\">iFFT</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/Dorothy__\" title=\"Expert Dorothy__\">Dorothy__</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/wfoifysaasisufgv\" title=\"Newbie wfoifysaasisufgv\">wfoifysaasisufgv</a></p></li> </ol><p><strong>Div. 1</strong></p> <ol> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/arvindf232\" title=\"Legendary Grandmaster arvindf232\"><span class=\"legendary-user-first-letter\">a</span>rvindf232</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Rubikun\" title=\"International Grandmaster Rubikun\">Rubikun</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Vercingetorix\" title=\"International Grandmaster Vercingetorix\">Vercingetorix</a></p></li> </ol><p><strong>UPD3.</strong> <a href=\"https://codeforces.com/blog/entry/120353\">Editorial.</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120240\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1867\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 897 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230855-120865\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230855\",\n blogEntryId: \"120240\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+280</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/salyg1n\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/salyg1n\">\n salyg1n\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120240#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120240#comments\">\n 218\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n\r\n<div class=\"pagination\">\r\n <ul>\r\n <span class=\"inactive\">←</span>\r\n <li>\r\n <span class=\"page-index active\" pageIndex=\"1\"><a href=\"/page/1\">1</a></span>\r\n </li>\r\n <li>\r\n <span class=\"page-index\" pageIndex=\"2\"><a href=\"/page/2\">2</a></span>\r\n </li>\r\n <li>\r\n <span 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Logging"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Logging</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The main server of Gomble company received a log of one top-secret process, the name of which can't be revealed. The log was written in the following format: ยซ<span class=\"tex-font-style-tt\">[date:time]: message</span>ยป, where for each ยซ<span class=\"tex-font-style-tt\">[date:time]</span>ยป value existed not more than 10 lines. All the files were encoded in a very complicated manner, and only one programmer โ Alex โ managed to decode them. The code was so complicated that Alex needed four weeks to decode it. Right after the decoding process was finished, all the files were deleted. But after the files deletion, Alex noticed that he saved the recordings in format ยซ<span class=\"tex-font-style-tt\">[time]: message</span>ยป. So, information about the dates was lost. However, as the lines were added into the log in chronological order, it's not difficult to say if the recordings could appear during one day or not. It is possible also to find the minimum amount of days during which the log was written.</p><p>So, to make up for his mistake Alex has to find the minimum amount of days covered by the log. Note that Alex doesn't have to find the minimum amount of days between the beginning and the end of the logging, he has to find the minimum amount of dates in which records could be done. (See Sample test 2 for further clarifications).</p><p>We should remind you that the process made not more than 10 recordings in a minute. Consider that a midnight belongs to coming day.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ100</span>). The following <span class=\"tex-span\"><i>n</i></span> lines contain recordings in format ยซ<span class=\"tex-font-style-tt\">[time]: message</span>ยป, where time is given in format ยซ<span class=\"tex-font-style-tt\">hh:mm x.m.</span>ยป. For <span class=\"tex-font-style-tt\">hh</span> two-digit numbers from <span class=\"tex-font-style-tt\">01</span> to <span class=\"tex-font-style-tt\">12</span> are used, for <span class=\"tex-font-style-tt\">mm</span> two-digit numbers from <span class=\"tex-font-style-tt\">00</span> to <span class=\"tex-font-style-tt\">59</span> are used, and <span class=\"tex-font-style-tt\">x</span> is either character ยซ<span class=\"tex-font-style-tt\">a</span>ยป or character ยซ<span class=\"tex-font-style-tt\">p</span>ยป. A message is a non-empty sequence of Latin letters and/or spaces, it doesn't start or end with a space. The length of each message doesn't exceed 20.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output one number โ the minimum amount of days covered by the log.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>[05:00 a.m.]: Server is started<br/>[05:00 a.m.]: Rescan initialized<br/>[01:13 p.m.]: Request processed<br/>[01:10 p.m.]: Request processed<br/>[11:40 p.m.]: Rescan completed<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>[09:00 a.m.]: User logged in<br/>[08:00 a.m.]: User logged in<br/>[07:00 a.m.]: User logged in<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Formally the 12-hour time format is described at: </p><ul> <li> <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/12-hour_clock</span>. </li></ul> The problem authors recommend you to look through these descriptions before you start with the problem.</div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"84330913f3980fec8462d0061f4cf7aa\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"09c09aef8ad5be2498175d65869f04dcf51f7d0b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='84330913f3980fec8462d0061f4cf7aa'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/16/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Implementation problems, programming technics, simulation\">\r\n implementation\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, KnuthโMorrisโPratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n 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$(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/422\" title=\"Codeforces Beta Round #16 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"96:97\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/431\" title=\"Codeforces Beta Round #16 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"706:707\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/16\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/16/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/16/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/16/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/16/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/16/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 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' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_7cbfe467e02ec7f110bdc80cb41fe810874b1090\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Logging</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The main server of Gomble company received a log of one top-secret process, the name of which can't be revealed. The log was written in the following format: ยซ<span class=\"tex-font-style-tt\">[date:time]: message</span>ยป, where for each ยซ<span class=\"tex-font-style-tt\">[date:time]</span>ยป value existed not more than 10 lines. All the files were encoded in a very complicated manner, and only one programmer โ Alex โ managed to decode them. The code was so complicated that Alex needed four weeks to decode it. Right after the decoding process was finished, all the files were deleted. But after the files deletion, Alex noticed that he saved the recordings in format ยซ<span class=\"tex-font-style-tt\">[time]: message</span>ยป. So, information about the dates was lost. However, as the lines were added into the log in chronological order, it's not difficult to say if the recordings could appear during one day or not. It is possible also to find the minimum amount of days during which the log was written.</p><p>So, to make up for his mistake Alex has to find the minimum amount of days covered by the log. Note that Alex doesn't have to find the minimum amount of days between the beginning and the end of the logging, he has to find the minimum amount of dates in which records could be done. (See Sample test 2 for further clarifications).</p><p>We should remind you that the process made not more than 10 recordings in a minute. Consider that a midnight belongs to coming day.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ100</span>). The following <span class=\"tex-span\"><i>n</i></span> lines contain recordings in format ยซ<span class=\"tex-font-style-tt\">[time]: message</span>ยป, where time is given in format ยซ<span class=\"tex-font-style-tt\">hh:mm x.m.</span>ยป. For <span class=\"tex-font-style-tt\">hh</span> two-digit numbers from <span class=\"tex-font-style-tt\">01</span> to <span class=\"tex-font-style-tt\">12</span> are used, for <span class=\"tex-font-style-tt\">mm</span> two-digit numbers from <span class=\"tex-font-style-tt\">00</span> to <span class=\"tex-font-style-tt\">59</span> are used, and <span class=\"tex-font-style-tt\">x</span> is either character ยซ<span class=\"tex-font-style-tt\">a</span>ยป or character ยซ<span class=\"tex-font-style-tt\">p</span>ยป. A message is a non-empty sequence of Latin letters and/or spaces, it doesn't start or end with a space. The length of each message doesn't exceed 20.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output one number โ the minimum amount of days covered by the log.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />[05:00 a.m.]: Server is started<br />[05:00 a.m.]: Rescan initialized<br />[01:13 p.m.]: Request processed<br />[01:10 p.m.]: Request processed<br />[11:40 p.m.]: Rescan completed<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />[09:00 a.m.]: User logged in<br />[08:00 a.m.]: User logged in<br />[07:00 a.m.]: User logged in<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>Formally the 12-hour time format is described at: </p><ul> <li> <span class=\"tex-font-style-tt\">http://en.wikipedia.org/wiki/12-hour_clock</span>. </li></ul> The problem authors recommend you to look through these descriptions before you start with the problem.</div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n 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class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2e03790445a5a5b0be02ccd5f8aaf33e'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> 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class=\"title\">\r\n <a href=\"/blog/entry/121025\"> <p>Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a>,\r\n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\"logo\" src=\"/predownloaded/e3/33/e333915aebea955b43b4ad17845f6dbf58875a0c.png\" style=\"float: right;height: 100.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></p><p>Sugeng enjing, <strong>Codeforces</strong>! ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ</p><p>COMPFEST 15 is happy to invite you to participate in <a href=\"/contest/1876\" title=\"Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)</a> and <a href=\"/contest/1877\" title=\"Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)</a> on <a class=\"contest-time\" contestid=\"1876\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=8&month=10&year=2023&hour=12&min=5&sec=0&p1=166\"><span class=\"format-time-with-dow\">Oct/08/2023 12:05 (Moscow time)</span></a>. Both rounds will be <strong>rated</strong>. You will be given <strong>2 hours and 30 minutes</strong> to solve <strong>7 problems</strong>.</p><h2><strong>Note the unusual time of the round</strong>.</h2><p>The problems are written by <a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-red\" href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\">Pyqe</a>, and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a>.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-legendary\" href=\"/profile/KAN\" title=\"Legendary Grandmaster KAN\"><span class=\"legendary-user-first-letter\">K</span>AN</a> for helping to host the round;</li> <li><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> and <a class=\"rated-user user-orange\" href=\"/profile/ScarletS\" title=\"Master ScarletS\">ScarletS</a> for the based coordination;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/gansixeneh\" title=\"Candidate Master gansixeneh\">gansixeneh</a> and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a> for helping with the problem preparation;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-blue\" href=\"/profile/CyberSleeper\" title=\"Expert CyberSleeper\">CyberSleeper</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Edbert.H\" title=\"Expert Edbert.H\">Edbert.H</a> for providing alternate solutions in the early stages;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for writing the Russian translations;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Aaeria\" title=\"Master Aaeria\">Aaeria</a>, <a class=\"rated-user user-blue\" href=\"/profile/AMnu\" title=\"Expert AMnu\">AMnu</a>, <a class=\"rated-user user-orange\" href=\"/profile/Berted\" title=\"Master Berted\">Berted</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-cyan\" href=\"/profile/buffering\" title=\"Specialist buffering\">buffering</a>, <a class=\"rated-user user-orange\" href=\"/profile/Drew_\" title=\"Master Drew_\">Drew_</a>, <a class=\"rated-user user-legendary\" href=\"/profile/dorijanlendvaj\" title=\"Legendary Grandmaster dorijanlendvaj\"><span class=\"legendary-user-first-letter\">d</span>orijanlendvaj</a>, <a class=\"rated-user user-orange\" href=\"/profile/eggag32\" title=\"Master eggag32\">eggag32</a>, <a class=\"rated-user user-violet\" href=\"/profile/Elben85\" title=\"Candidate Master Elben85\">Elben85</a>, <a class=\"rated-user user-red\" href=\"/profile/emorgan5289\" title=\"International Grandmaster emorgan5289\">emorgan5289</a>, <a class=\"rated-user user-orange\" href=\"/profile/faustaadp\" title=\"Master faustaadp\">faustaadp</a>, <a class=\"rated-user user-red\" href=\"/profile/ffao\" title=\"International Grandmaster ffao\">ffao</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-legendary\" href=\"/profile/gamegame\" title=\"Legendary Grandmaster gamegame\"><span class=\"legendary-user-first-letter\">g</span>amegame</a>, <a class=\"rated-user user-violet\" href=\"/profile/hocky\" title=\"Candidate Master hocky\">hocky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Insta-x\" title=\"Expert Insta-x\">Insta-x</a>, <a class=\"rated-user user-red\" href=\"/profile/jdurie\" title=\"Grandmaster jdurie\">jdurie</a>, <a class=\"rated-user user-orange\" href=\"/profile/joelgun14\" title=\"Master joelgun14\">joelgun14</a>, <a class=\"rated-user user-violet\" href=\"/profile/KerakTelor\" title=\"Candidate Master KerakTelor\">KerakTelor</a>, <a class=\"rated-user user-blue\" href=\"/profile/Marky\" title=\"Expert Marky\">Marky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Murinh0\" title=\"Expert Murinh0\">Murinh0</a>, <a class=\"rated-user user-red\" href=\"/profile/nvmdava\" title=\"Grandmaster nvmdava\">nvmdava</a>, <a class=\"rated-user user-orange\" href=\"/profile/nyab\" title=\"Master nyab\">nyab</a>, <a class=\"rated-user user-orange\" href=\"/profile/Owmicron\" title=\"Master Owmicron\">Owmicron</a>, <a class=\"rated-user user-red\" href=\"/profile/prvocislo\" title=\"Grandmaster prvocislo\">prvocislo</a>, <a class=\"rated-user user-red\" href=\"/profile/PurpleCrayon\" title=\"International Grandmaster PurpleCrayon\">PurpleCrayon</a>, <a class=\"rated-user user-red\" href=\"/profile/rama_pang\" title=\"Grandmaster rama_pang\">rama_pang</a>, <a class=\"rated-user user-blue\" href=\"/profile/TakeMe\" title=\"Expert TakeMe\">TakeMe</a>, <a class=\"rated-user user-blue\" href=\"/profile/sahil_k\" title=\"Expert sahil_k\">sahil_k</a>, <a class=\"rated-user user-red\" href=\"/profile/user202729_\" title=\"International Grandmaster user202729_\">user202729_</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-green\" href=\"/profile/WHCPP\" title=\"Pupil WHCPP\">WHCPP</a>, and <a class=\"rated-user user-violet\" href=\"/profile/ZeroScar\" title=\"Candidate Master ZeroScar\">ZeroScar</a> for testing the contest and providing us very useful feedback;</li> <li>Universitas Indonesia, all the local committees, administrators, and managers of the whole COMPFEST event;</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Codeforces and Polygon platform!</li> </ul><p>COMPFEST itself is an annual event hosted by Universitas Indonesia. It is the largest student-run IT event in Indonesia and competitive programming contest is one of the competitions hosted.</p><p>We hope you will enjoy and have fun in the contest. Muga-muga beja lan isa entuk biji apik!! ๐ช๐ช๐ฅ๐ฅ</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121025\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1876\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1877\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final 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of complaintReasons) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", complaintReason.id);\n $li.find(\"span\")\n .html(getLocalizedName(complaintReason)\n + \" <i class=\\\"icon-question-sign clickable-title\\\" title=\\\"\"\n + getLocalizedDescription(complaintReason)\n + \"\\\"></i>\")\n .attr(\"title\", getLocalizedDescription(complaintReason));\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n if (complaint && complaint.complaintReasonId === complaintReason.id) {\n $li.find(\"input[name=complaintReasonId]\").attr(\"checked\", \"checked\");\n }\n $li.find(\".clickable-title\").click(function () {\n alert(getLocalizedDescription(complaintReason));\n return false;\n }).css(\"position\", \"relative\").css(\"bottom\", \"1px\").css(\"font-size\", \"12px\");\n }\n\n if (complaint) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", 0);\n $li.find(\"span\").html(\"Delete complaint\");\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n }\n\n $popup.find(\"._ComplaintFrame_submitForm\").submit(function () {\n const complaintReasonId = $popup.find(\"input[name=complaintReasonId]:checked\").val();\n if (complaintReasonId === undefined) {\n alert(\"Please select complaint reason\");\n return false;\n }\n\n $.post(\"/data/complaint\", {\n action: \"newComplaint\",\n targetClass: targetClass,\n targetId: targetId,\n complaintReasonId: complaintReasonId\n }, function (response) {\n if (response.success === \"true\") {\n Codeforces.showMessage(\"Complaint has been created\");\n $.facebox.close();\n }\n }, \"json\");\n\n return false;\n });\n }\n }, \"json\");\n\n return false;\n });\n}); </script>\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Pyqe\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Pyqe\">\n Pyqe\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121025#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121025#comments\">\n 41\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121739\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/121114\"> <p>Codeforces Command Lines (2023-10-06)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\" class=\"rated-user user-blue\">Vladosiya</a>,\r\n <a href=\"/topic/121739/en7\">history</a>,\r\n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>We've compiled a list of command lines that Codeforces uses to compile and run solutions in various languages and compilers.</p><p>It is up-to-date as of today (2023-10-06), and we will make efforts to keep it current in the future, but this is not guaranteed.</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121114\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-73866-121739\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"73866\",\n blogEntryId: \"121114\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compilers\" class=\"tag notice\" style=\"text-decoration: none;\">compilers</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compiler+options\" class=\"tag notice\" style=\"text-decoration: none;\">compiler options</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=languages\" class=\"tag notice\" style=\"text-decoration: none;\">languages</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+235</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n <div style=\"position: relative; float: left; left: -1.5rem; top: 1rem;\">\r\n\n\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Vladosiya\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Vladosiya\">\n Vladosiya\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121114#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121114#comments\">\n 8\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121449\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120824\"> <p>Codeforces Round 901 (Div. 1, Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a>,\r\n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I'm pleased to invite you to <a href=\"/contest/1874\" title=\"Codeforces Round 901 (Div. 1)\">Codeforces Round 901 (Div. 1)</a> and <a href=\"/contest/1875\" title=\"Codeforces Round 901 (Div. 2)\">Codeforces Round 901 (Div. 2)</a>. It starts on <a class=\"contest-time\" contestid=\"1874\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=30&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/30/2023 17:35 (Moscow time)</span></a>. It also means, the National Day of China arrives during the round. Wish you a nice vacation! ๐๐๐</p><p>For both divisions, you will have <strong>3 hours</strong> to solve <strong>7 problems</strong>.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his wonderful coordination.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for Russian translation and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for helping us with Russian clarifications.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\">GeZhiyuan</a> for providing all the problems and "a few" rejected problems.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> and <a class=\"rated-user user-red\" href=\"/profile/SanweiTreap\" title=\"Grandmaster SanweiTreap\">SanweiTreap</a> for helping me prepare the problems.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a>, <a class=\"rated-user user-legendary\" href=\"/profile/wangziji\" title=\"Legendary Grandmaster wangziji\"><span class=\"legendary-user-first-letter\">w</span>angziji</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> and <a class=\"rated-user user-legendary\" href=\"/profile/flowerletter\" title=\"Legendary Grandmaster flowerletter\"><span class=\"legendary-user-first-letter\">f</span>lowerletter</a> for Legendary Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/sjcsjcsjc\" title=\"International Grandmaster sjcsjcsjc\">sjcsjcsjc</a>, <a class=\"rated-user user-red\" href=\"/profile/He_Ren\" title=\"International Grandmaster He_Ren\">He_Ren</a>, <a class=\"rated-user user-red\" href=\"/profile/GaryZ005\" title=\"International Grandmaster GaryZ005\">GaryZ005</a>, <a class=\"rated-user user-red\" href=\"/profile/platelet\" title=\"International Grandmaster platelet\">platelet</a>, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a>, <a class=\"rated-user user-red\" href=\"/profile/thenymphsofdelphi\" title=\"International Grandmaster thenymphsofdelphi\">thenymphsofdelphi</a>, <a class=\"rated-user user-red\" href=\"/profile/DerekFeng\" title=\"International Grandmaster DerekFeng\">DerekFeng</a>, <a class=\"rated-user user-red\" href=\"/profile/Juanzhang\" title=\"International Grandmaster Juanzhang\">Juanzhang</a> and <a class=\"rated-user user-red\" href=\"/profile/ttklwxx\" title=\"International Grandmaster ttklwxx\">ttklwxx</a> for International Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/juju527\" title=\"Grandmaster juju527\">juju527</a>, <a class=\"rated-user user-red\" href=\"/profile/zimpha\" title=\"Grandmaster zimpha\">zimpha</a>, <a class=\"rated-user user-red\" href=\"/profile/765\" title=\"Grandmaster 765\">765</a>, <a class=\"rated-user user-red\" href=\"/profile/xuanquang1999\" title=\"Grandmaster xuanquang1999\">xuanquang1999</a>, <a class=\"rated-user user-red\" href=\"/profile/CrTsIr\" title=\"Grandmaster CrTsIr\">CrTsIr</a> and <a class=\"rated-user user-red\" href=\"/profile/EasonTAO\" title=\"Grandmaster EasonTAO\">EasonTAO</a> for Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/SATSKY\" title=\"Master SATSKY\">SATSKY</a>, <a class=\"rated-user user-orange\" href=\"/profile/lanhf\" title=\"Master lanhf\">lanhf</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hank2019\" title=\"Master Hank2019\">Hank2019</a> and <a class=\"rated-user user-orange\" href=\"/profile/Yakumo_Ran\" title=\"Master Yakumo_Ran\">Yakumo_Ran</a> for Master Testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/DaniraSilla\" title=\"Candidate Master DaniraSilla\">DaniraSilla</a> and <a class=\"rated-user user-violet\" href=\"/profile/kriepiekrollie\" title=\"Candidate Master kriepiekrollie\">kriepiekrollie</a> for Candidate Master Testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/raulandreipop\" title=\"Expert raulandreipop\">raulandreipop</a>, <a class=\"rated-user user-blue\" href=\"/profile/micho\" title=\"Expert micho\">micho</a>, <a class=\"rated-user user-blue\" href=\"/profile/alwyn\" title=\"Expert alwyn\">alwyn</a>, <a class=\"rated-user user-blue\" href=\"/profile/ArgintLaAnu\" title=\"Expert ArgintLaAnu\">ArgintLaAnu</a>, <a class=\"rated-user user-blue\" href=\"/profile/IssamOtoz\" title=\"Expert IssamOtoz\">IssamOtoz</a> and <a class=\"rated-user user-blue\" href=\"/profile/jakao\" title=\"Expert jakao\">jakao</a> for Expert Testing.</p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/CLown1331\" title=\"Pupil CLown1331\">CLown1331</a> for Pupil Testing.</p></li> <li><p>You for participating the round.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</p></li> </ul><p>Especially, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his great contribution to the round, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a> for providing user solutions for all the problems, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> for making the announcement and tutorial more readable.</p><p>Finally and most importantly, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> for helping me with everything patiently all the time. This round can't happen without him.</p><p>The main character of the problems will be Jellyfish, a sweet little girl. ๐๐๐</p><p>Score distribution:</p> <ul> <li><p>Div.1: $$$500$$$ โ $$$1250$$$ โ $$$1500$$$ โ $$$2250$$$ โ $$$3000$$$ โ $$$4000$$$ โ $$$5000$$$</p></li> <li><p>Div.2: $$$500$$$ โ $$$1000$$$ โ $$$1000$$$ โ $$$1250$$$ โ $$$2000$$$ โ $$$2250$$$ โ $$$3000$$$</p></li> </ul><p>Good Luck & Have Fun! ๐ฅ๐ฅ๐ฅ</p><p><strong>UPD1:</strong> <a href=\"https://codeforces.com/blog/entry/120943\">Editorial</a> is out.</p><p><strong>UPD2:</strong> Congratulations to the winners!</p> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\"><span class=\"legendary-user-first-letter\">B</span>enq</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Qingyu\" title=\"International Grandmaster Qingyu\">Qingyu</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/amiya\" title=\"Legendary Grandmaster amiya\"><span class=\"legendary-user-first-letter\">a</span>miya</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/RollingPanda\" title=\"Newbie RollingPanda\">RollingPanda</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/WanYuanShenWanDe\" title=\"Newbie WanYuanShenWanDe\">WanYuanShenWanDe</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-red\" href=\"/profile/H_stove\" title=\"Grandmaster H_stove\">H_stove</a></p><p>B. <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>C. <a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></p><p>D. <a class=\"rated-user user-red\" href=\"/profile/ooOAM\" title=\"Grandmaster ooOAM\">ooOAM</a></p><p>E. <a class=\"rated-user user-orange\" href=\"/profile/Salley-Garden\" title=\"Master Salley-Garden\">Salley-Garden</a></p><p>F. <a class=\"rated-user user-red\" href=\"/profile/i_will_be_less_than_blue\" title=\"Grandmaster i_will_be_less_than_blue\">i_will_be_less_than_blue</a></p><p>G. <a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a> (after the contest)</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-blue\" href=\"/profile/Azaml\" title=\"Expert Azaml\">Azaml</a></p><p>B. <a class=\"rated-user user-blue\" href=\"/profile/Shirotsume\" title=\"Expert Shirotsume\">Shirotsume</a></p><p>C. <a class=\"rated-user user-gray\" href=\"/profile/viveksingh912\" title=\"Newbie viveksingh912\">viveksingh912</a></p><p>D. <a class=\"rated-user user-gray\" href=\"/profile/kaiboy\" title=\"Newbie kaiboy\">kaiboy</a></p><p>E. <a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p><p>F. <a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p><p>G. <a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></div></div></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120824\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1874\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1875\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-238039-121449\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"238039\",\n blogEntryId: \"120824\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+165</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/GeZhiyuan\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/GeZhiyuan\">\n GeZhiyuan\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120824#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120824#comments\">\n 231\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121303\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120678\"> <p>Codeforces Round #900 (Div. 3)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AlphaMale06\" title=\"Specialist AlphaMale06\" class=\"rated-user user-cyan\">AlphaMale06</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p><a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a> and I are glad to invite you to the <a href=\"/contest/1878\" title=\"Codeforces Round 900 (Div. 3)\">Codeforces Round 900 (Div. 3)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1878\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=26&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/26/2023 17:35 (Moscow time)</span></a></p><p>You will be given <strong>7 problems</strong> and <strong>2 hours and 15 minutes</strong> to solve them.</p><p>Note that the <strong>penalty</strong> for the wrong submission in this round is <strong>10 minutes</strong>.</p><p>Also note that there will be a <strong>12 hour open hacking phase</strong> after the round.</p><p><a href=\"https://codeforces.com/blog/entry/59228\">Remember</a>, that only the <em>trusted participants of the third division</em> will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a <em>trusted participant of the third division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them)</li> <li>do not have a point of 1900 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, the round will be rated for you.</strong></p><p>Problems have been created and prepared by <a class=\"rated-user user-blue\" href=\"/profile/AlphaMale06\" title=\"Expert AlphaMale06\">AlphaMale06</a>, <a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>.</p><p>We would also to thank:</p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for the amazing coordination and help with preparing a balanced problemset, and for giving us the opportunity to create a Div. 3 round.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Polygon and Codeforces platforms.</li> <li><a class=\"rated-user user-red\" href=\"/profile/JovanB\" title=\"Grandmaster JovanB\">JovanB</a>, <a class=\"rated-user user-red\" href=\"/profile/abc864197532\" title=\"International Grandmaster abc864197532\">abc864197532</a>, <a class=\"rated-user user-red\" href=\"/profile/sevlll777\" title=\"Grandmaster sevlll777\">sevlll777</a> for red testing</li> <li><a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>, <a class=\"rated-user user-orange\" href=\"/profile/n0sk1ll\" title=\"Master n0sk1ll\">n0sk1ll</a>, <a class=\"rated-user user-orange\" href=\"/profile/allllekssssa\" title=\"Master allllekssssa\">allllekssssa</a>, <a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a>, <a class=\"rated-user user-orange\" href=\"/profile/misorin\" title=\"International Master misorin\">misorin</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hyperbolic\" title=\"International Master Hyperbolic\">Hyperbolic</a> for yellow testing</li> <li><a class=\"rated-user user-violet\" href=\"/profile/DAleksa\" title=\"Candidate Master DAleksa\">DAleksa</a>, <a class=\"rated-user user-violet\" href=\"/profile/ljuba\" title=\"Candidate Master ljuba\">ljuba</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex.kudryashov\" title=\"Candidate Master alex.kudryashov\">alex.kudryashov</a> for purple testing</li> <li><a class=\"rated-user user-blue\" href=\"/profile/MihailoT\" title=\"Expert MihailoT\">MihailoT</a>, <a class=\"rated-user user-blue\" href=\"/profile/SashaT9\" title=\"Expert SashaT9\">SashaT9</a>, <a class=\"rated-user user-blue\" href=\"/profile/ELDRVD\" title=\"Expert ELDRVD\">ELDRVD</a>, <a class=\"rated-user user-blue\" href=\"/profile/Chrisedyong\" title=\"Expert Chrisedyong\">Chrisedyong</a>, <a class=\"rated-user user-blue\" href=\"/profile/tryptophan\" title=\"Expert tryptophan\">tryptophan</a> for blue testing</li> <li><a class=\"rated-user user-cyan\" href=\"/profile/Andrijanikolic73\" title=\"Specialist Andrijanikolic73\">Andrijanikolic73</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Mihajlo18\" title=\"Specialist Mihajlo18\">Mihajlo18</a>, <a class=\"rated-user user-cyan\" href=\"/profile/UrosNedic\" title=\"Specialist UrosNedic\">UrosNedic</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Klaus26\" title=\"Specialist Klaus26\">Klaus26</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Escaquejant\" title=\"Specialist Escaquejant\">Escaquejant</a>, <a class=\"rated-user user-cyan\" href=\"/profile/smax294\" title=\"Specialist smax294\">smax294</a>, <a class=\"rated-user user-cyan\" href=\"/profile/max0n\" title=\"Specialist max0n\">max0n</a> for cyan testing</li> <li><a class=\"rated-user user-gray\" href=\"/profile/Budimmm\" title=\"Newbie Budimmm\">Budimmm</a> for gray testing</li> </ol><p>Also a very special thanks to the most dedicated tester I have ever seen, <a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>.</p><p>I wish you luck, and hope you like the problems and learn from them.</p><p>Update: <a href=\"https://codeforces.com/blog/entry/120813\">Editorial</a> is out.</p><p>Congratulations to the winners:</p><p>Unofficial:</p> <ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/SSerxhs\" title=\"International Grandmaster SSerxhs\">SSerxhs</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/neal\" title=\"Legendary Grandmaster neal\"><span class=\"legendary-user-first-letter\">n</span>eal</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/risujiroh\" title=\"International Grandmaster risujiroh\">risujiroh</a></p></li> </ol><p>Official:</p> <ol> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/hackerjohn\" title=\"Specialist hackerjohn\">hackerjohn</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/wahb\" title=\"Specialist wahb\">wahb</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/kutcoder\" title=\"Specialist kutcoder\">kutcoder</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Sxy_Limit\" title=\"Specialist Sxy_Limit\">Sxy_Limit</a></p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/not_rainboy\" title=\"Pupil not_rainboy\">not_rainboy</a></p></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120678\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1878\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 900 (Div. 3)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-269459-121303\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"269459\",\n blogEntryId: \"120678\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+192</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AlphaMale06\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AlphaMale06\">\n AlphaMale06\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120678#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120678#comments\">\n 347\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121269\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120644\"> <p>Codeforces Round 899 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a>,\r\n <a href=\"/topic/121269/en9\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I am pleased to invite you to participate in <a href=\"/contest/1882\" title=\"Codeforces Round 899 (Div. 2)\">Codeforces Round 899 (Div. 2)</a>, which will be held on <a class=\"contest-time\" contestid=\"1882\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=25&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/25/2023 17:35 (Moscow time)</span></a>.</p><p>All problems were written and prepared by me.</p><p>You will be given <strong>5 problems, and one of them is divided into two subtasks</strong>. You will have <strong>2 hours</strong> to solve them.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-orange\" href=\"/profile/irkstepanov\" title=\"International Master irkstepanov\">irkstepanov</a> for excellent coordination and Russian translation!</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for providing useful feedbacks.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a> for helping me much with one problem of the contest.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/ko_osaga\" title=\"Legendary Grandmaster ko_osaga\"><span class=\"legendary-user-first-letter\">k</span>o_osaga</a> for Nutella testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/leinad2\" title=\"Grandmaster leinad2\">leinad2</a>, <a class=\"rated-user user-red\" href=\"/profile/Numbering\" title=\"Grandmaster Numbering\">Numbering</a>, <a class=\"rated-user user-red\" href=\"/profile/qwerasdfzxcl\" title=\"International Grandmaster qwerasdfzxcl\">qwerasdfzxcl</a>, <a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a>, <a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for Red testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Kaling\" title=\"Master Kaling\">Kaling</a>, <a class=\"rated-user user-orange\" href=\"/profile/Mingyu331\" title=\"Master Mingyu331\">Mingyu331</a>, <a class=\"rated-user user-orange\" href=\"/profile/chaeyihwan\" title=\"International Master chaeyihwan\">chaeyihwan</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kawaii2DIdolOfGSHS\" title=\"International Master Kawaii2DIdolOfGSHS\">Kawaii2DIdolOfGSHS</a>, <a class=\"rated-user user-orange\" href=\"/profile/azberjibiou\" title=\"International Master azberjibiou\">azberjibiou</a>, <a class=\"rated-user user-orange\" href=\"/profile/mjhmjh1104\" title=\"Master mjhmjh1104\">mjhmjh1104</a>, <a class=\"rated-user user-orange\" href=\"/profile/DELTARUNE\" title=\"Master DELTARUNE\">DELTARUNE</a>, <a class=\"rated-user user-orange\" href=\"/profile/wuhudsm\" title=\"Master wuhudsm\">wuhudsm</a>, <a class=\"rated-user user-orange\" href=\"/profile/hypergraph_coloring\" title=\"International Master hypergraph_coloring\">hypergraph_coloring</a> for Orange testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/unordered_map\" title=\"Candidate Master unordered_map\">unordered_map</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex0211\" title=\"Candidate Master alex0211\">alex0211</a>, <a class=\"rated-user user-violet\" href=\"/profile/gs20036\" title=\"Candidate Master gs20036\">gs20036</a>, <a class=\"rated-user user-violet\" href=\"/profile/namolbbaemi\" title=\"Candidate Master namolbbaemi\">namolbbaemi</a>, <a class=\"rated-user user-violet\" href=\"/profile/eeeDA\" title=\"Candidate Master eeeDA\">eeeDA</a>, <a class=\"rated-user user-violet\" href=\"/profile/nlog\" title=\"Candidate Master nlog\">nlog</a> for Purple testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/andyandy\" title=\"Expert andyandy\">andyandy</a>, <a class=\"rated-user user-blue\" href=\"/profile/JaewonOh\" title=\"Expert JaewonOh\">JaewonOh</a>, <a class=\"rated-user user-blue\" href=\"/profile/KongUm\" title=\"Expert KongUm\">KongUm</a>, <a class=\"rated-user user-blue\" href=\"/profile/Coruncanius\" title=\"Expert Coruncanius\">Coruncanius</a>, <a class=\"rated-user user-blue\" href=\"/profile/ez_code\" title=\"Expert ez_code\">ez_code</a>, <a class=\"rated-user user-blue\" href=\"/profile/fs_edge\" title=\"Expert fs_edge\">fs_edge</a>, <a class=\"rated-user user-blue\" href=\"/profile/chromate00\" title=\"Expert chromate00\">chromate00</a> for Blue testing.</p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/Hanlana18\" title=\"Newbie Hanlana18\">Hanlana18</a>, <a class=\"rated-user user-gray\" href=\"/profile/papergundam\" title=\"Newbie papergundam\">papergundam</a>, <a class=\"rated-user user-gray\" href=\"/profile/sjmjys954646\" title=\"Newbie sjmjys954646\">sjmjys954646</a> for Gray testing.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for great Polygon and Codeforces platforms!</p></li> <li><p>And last but not least, <a class=\"rated-user user-legendary\" href=\"https://codeforces.com/profile/\">You</a> for participating in the round!</p></li> </ul><p>Score distribution: $$$500 - 1000 - 1500 - 2000 - (2000 + 2000)$$$</p><p>Good luck and enjoy the round!</p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120792\">Editorial</a> is out. </p><p><strong>UPD2</strong>: Congratulations to the winners!</p><p><strong>Official Contestants</strong></p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Lycorisqwq\" title=\"Expert Lycorisqwq\">Lycorisqwq</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/zepto\" title=\"Unrated, zepto\">zepto</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/vjudge39\" title=\"Unrated, vjudge39\">vjudge39</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/Beelzebub_blue\" title=\"Candidate Master Beelzebub_blue\">Beelzebub_blue</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/_t_W_\" title=\"Candidate Master _t_W_\">_t_W_</a></li> </ol><p><strong>Official + Unofficial Contestants</strong></p> <ol> <li><a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/antontrygubO_o\" title=\"International Grandmaster antontrygubO_o\">antontrygubO_o</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a></li> <li><a class=\"rated-user user-orange\" href=\"/profile/KumaTachiRen\" title=\"Master KumaTachiRen\">KumaTachiRen</a></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120644\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1882\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 899 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-272374-121269\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"272374\",\n blogEntryId: \"120644\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+524</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/windva\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/windva\">\n windva\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120644#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120644#comments\">\n 188\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121316\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120691\"> <p>Educational Codeforces Round 155 [Rated for Div. 2]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a>,\r\n <a href=\"/topic/121316/en5\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p>On <a class=\"contest-time\" contestid=\"1879\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=24&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/24/2023 17:35 (Moscow time)</span></a> <a href=\"/contest/1879\" title=\"Educational Codeforces Round 155 (Rated for Div. 2)\">Educational Codeforces Round 155 (Rated for Div. 2)</a> will start.</p><p>Series of Educational Rounds continue being held as <a href=\"https://harbour.space/\">Harbour.Space University</a> initiative! You can read the details about the cooperation between <a href=\"https://harbour.space/\">Harbour.Space University</a> and Codeforces in the <a href=\"https://mirror.codeforces.com/blog/entry/51208\">blog post</a>.</p><p>This round will be <strong>rated for the participants with rating lower than 2100</strong>. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.</p><p>You will be given <strong>6 or 7 problems</strong> and <strong>2 hours</strong> to solve them.</p><p>The problems were invented and prepared by Adilbek <a class=\"rated-user user-orange\" href=\"/profile/adedalic\" title=\"International Master adedalic\">adedalic</a> Dalabaev, Ivan <a class=\"rated-user user-red\" href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\">BledDest</a> Androsov, Maksim <a class=\"rated-user user-violet\" href=\"/profile/Neon\" title=\"Candidate Master Neon\">Neon</a> Mescheryakov, Roman <a class=\"rated-user user-orange\" href=\"/profile/Roms\" title=\"Master Roms\">Roms</a> Glazov and me. Also, huge thanks to Mike <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> Mirzayanov for great systems Polygon and Codeforces.</p><p>Good luck to all the participants!</p><p>Our friends at Harbour.Space also have a message for you:</p> <center><img alt=\"Harbour.Space\" src=\"/predownloaded/29/a4/29a4884273346021dec6559e9785af37a662cc56.png\" style=\"height: 200.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></center> <center style=\"margin: 1.0em;\"><b>FULLY FUNDED SCHOLARSHIPS for Masters in Data Science and Computer Science </b></center><p><em>Scholarships for Master's students in <a href=\"https://harbour.space/computer-science\">Computer Science</a> and <a href=\"https://harbour.space/data-science\">Data Science</a> are available in <a href=\"https://harbour.space\">Harbour.Space University</a> Barcelona campus!</em> </p><p><strong>Scholarship Summary:</strong></p> <ul> <li><em>Fully funded scholarship (29.900 โฌ/year) to study a Masterโs degree in Data Science or Computer Science for two years</em></li> <li><em>Successful applicants will become part of the Universityโs โTalent poolโ and will be shown to the sponsoring companies. In case the candidate is picked for the Work&Study Program from our industry partner, the student starts an internship with a commitment to study 3 hours/day and work for 4 hour/day</em></li> </ul><p><em>Please note preselected candidates will be requested to pay a non-refundable application fee of 85โฌ to study at Harbour.Space University.</em></p><p><em><strong>Candidateโs commitment:</strong></em></p><p><em>You will complete 15 modules (each three weeks long) in one year. The daily class workload is 3 hours, plus homework to complete in your own time.</em></p><p><em><strong>Candidateโs requirements:</strong></em> </p> <ul> <li><em>Bachelor's degree in the field of Mathematics, Statistics, Data Science, Computer Science or similar</em></li> <li><em>English proficiency</em></li> <li><em>Advanced knowledge and experience in Python, SQL, Spark/Scala, and bash</em></li> <li><em>Experienced use of Big Data technologies: Spark, HDFS, Kafka, etc.</em></li> <li><em>Hands-on experience with Data Science techniques: feature engineering,</em></li> <li><em>Strong ML knowledge</em></li> <li><em>Strong Software Engineering Background</em></li> <li><em>Problem-solving aptitude</em></li> </ul> <center style=\"margin: 2.5em;\"> <a href=\"https://harbour.space/account/apply-process?utm_source=codeforces&utm_medium=partner&utm_campaign=bcn_b2b\" style=\"text-decoration: none;font-size: 14.0px;background-color: rgb(98,91,183);color: white;font-weight: bold;padding: 0.5em 1.0em;\">Apply here โ</a> </center><p><strong>UPD:</strong> <a href=\"https://codeforces.com/blog/entry/120773\">Editorial is out</a> </p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120691\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1879\" class=\"notice\" style=\"text-decoration: none;\">Educational Codeforces Round 155 (Rated for Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-42750-121316\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"42750\",\n blogEntryId: \"120691\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+245</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/awoo\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/awoo\">\n awoo\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120691#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120691#comments\">\n 189\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121227\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120602\"> <p>Codeforces Round 898 (Div. 4)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/mesanu\" title=\"Candidate Master mesanu\" class=\"rated-user user-violet\">mesanu</a>,\r\n <a href=\"/topic/121227/en2\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p><a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and I want to invite you to <a href=\"/contest/1873\" title=\"Codeforces Round 898 (Div. 4)\">Codeforces Round 898 (Div. 4)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1873\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=21&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/21/2023 17:35 (Moscow time)</span></a>.</p><p>The format of the event will be identical to Div. 3 rounds:</p> <ul> <li>5-8 tasks;</li> <li>ICPC rules with a penalty of 10 minutes for an incorrect submission;</li> <li>12-hour phase of open hacks after the end of the round (hacks do not give additional points)</li> <li>after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated</li> <li>by default, only "trusted" participants are shown in the results table (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).</li> </ul><p>We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.</p><p>Only <em>trusted participants of the fourth division</em> will be included in the official standings table. This is a forced measure for combating unsporting behaviour. To qualify as <em>a trusted participant of the fourth division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them),</li> <li>do not have a point of 1400 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), then the round will be rated for you.</strong></p><p>Many thanks to the testers: <a class=\"rated-user user-orange\" href=\"/profile/Gheal\" title=\"Master Gheal\">Gheal</a>, <a class=\"rated-user user-orange\" href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\">Phantom_Performer</a>, <a class=\"rated-user user-orange\" href=\"/profile/KrowSavcik\" title=\"Master KrowSavcik\">KrowSavcik</a>, <a class=\"rated-user user-cyan\" href=\"/profile/haochenkang\" title=\"Specialist haochenkang\">haochenkang</a>, <a class=\"rated-user user-cyan\" href=\"/profile/sandry24\" title=\"Specialist sandry24\">sandry24</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>, <a class=\"rated-user user-violet\" href=\"/profile/NintsiChkhaidze\" title=\"Candidate Master NintsiChkhaidze\">NintsiChkhaidze</a>, <a class=\"rated-user user-orange\" href=\"/profile/erekle\" title=\"International Master erekle\">erekle</a>, <a class=\"rated-user user-red\" href=\"/profile/Dominater069\" title=\"Grandmaster Dominater069\">Dominater069</a>, <a class=\"rated-user user-blue\" href=\"/profile/MADE_IN_HEAVEN\" title=\"Expert MADE_IN_HEAVEN\">MADE_IN_HEAVEN</a>, <a class=\"rated-user user-blue\" href=\"/profile/Qualified\" title=\"Expert Qualified\">Qualified</a>.</p><p>We suggest reading all of the problems and hope you will find them interesting!</p><p><strong>Good Luck!</strong></p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120634\">Editorial is out!</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120602\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1873\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 898 (Div. 4)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-188642-121227\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"188642\",\n blogEntryId: \"120602\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+200</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/mesanu\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/mesanu\">\n mesanu\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120602#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120602#comments\">\n 179\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121083\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120458\"> <p>CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/glebustim\" title=\"Grandmaster glebustim\" class=\"rated-user user-red\">glebustim</a>,\r\n <a href=\"/topic/121083/en8\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3>Hello, Codeforces!</h3><p><a class=\"rated-user user-red\" href=\"/profile/SomethingNew\" title=\"International Grandmaster SomethingNew\">SomethingNew</a> and I are glad to invite you to <a href=\"/contest/1870\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a>, which will take place on <a class=\"contest-time\" contestid=\"1870\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=18&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/18/2023 17:35 (Moscow time)</span></a>. You will have 2 hours 15 minutes to solve 8 problems. The round will be rated for everyone.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-orange\" href=\"/profile/74TrAkToR\" title=\"International Master 74TrAkToR\">74TrAkToR</a> for coordinating this round.</li> <li><a class=\"rated-user user-legendary\" href=\"/profile/isaf27\" title=\"Legendary Grandmaster isaf27\"><span class=\"legendary-user-first-letter\">i</span>saf27</a>, <a class=\"rated-user user-legendary\" href=\"/profile/ugly2333\" title=\"Legendary Grandmaster ugly2333\"><span class=\"legendary-user-first-letter\">u</span>gly2333</a>, <a class=\"rated-user user-red\" href=\"/profile/DataStructures\" title=\"Grandmaster DataStructures\">DataStructures</a>, <a class=\"rated-user user-red\" href=\"/profile/Little09\" title=\"International Grandmaster Little09\">Little09</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kieray\" title=\"Master Kieray\">Kieray</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-orange\" href=\"/profile/Dart-Xeyter\" title=\"International Master Dart-Xeyter\">Dart-Xeyter</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/meowcneil\" title=\"Master meowcneil\">meowcneil</a>, <a class=\"rated-user user-orange\" href=\"/profile/127.0.0.1\" title=\"Master 127.0.0.1\">127.0.0.1</a>, <a class=\"rated-user user-violet\" href=\"/profile/Nanani\" title=\"Candidate Master Nanani\">Nanani</a>, <a class=\"rated-user user-violet\" href=\"/profile/nnv-nick\" title=\"Candidate Master nnv-nick\">nnv-nick</a>, <a class=\"rated-user user-violet\" href=\"/profile/SomethingDifferent\" title=\"Candidate Master SomethingDifferent\">SomethingDifferent</a>, <a class=\"rated-user user-blue\" href=\"/profile/vl342\" title=\"Expert vl342\">vl342</a>, <a class=\"rated-user user-blue\" href=\"/profile/shiv_codegen\" title=\"Expert shiv_codegen\">shiv_codegen</a>, <a class=\"rated-user user-cyan\" href=\"/profile/M1lkas\" title=\"Specialist M1lkas\">M1lkas</a>, <a class=\"rated-user user-green\" href=\"/profile/allmath\" title=\"Pupil allmath\">allmath</a>, <a class=\"rated-user user-gray\" href=\"/profile/sdyakonov\" title=\"Newbie sdyakonov\">sdyakonov</a> for testing the round and providing useful feedback.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</li> </ul><h4><strong>Score distribution:</strong></h4><p>500 โ 750 โ 1500 โ 1750 โ 2750 โ 3250 โ 3250 โ 4000</p><p>We hope that our problems will be interesting for you!</p><h4><a href=\"https://codeforces.com/blog/entry/120524\">Editorial</a></h4><p><strong>Congratulations to the winners!</strong></p> <ol> <li><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/emptyhope\" title=\"Legendary Grandmaster emptyhope\"><span class=\"legendary-user-first-letter\">e</span>mptyhope</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/maspy\" title=\"International Grandmaster maspy\">maspy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/AoLiGei\" title=\"Legendary Grandmaster AoLiGei\"><span class=\"legendary-user-first-letter\">A</span>oLiGei</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/noimi\" title=\"Legendary Grandmaster noimi\"><span class=\"legendary-user-first-letter\">n</span>oimi</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></li> </ol><p>And here is the information from our title sponsor:</p><p><img src=\"/predownloaded/ce/9f/ce9f87d5c429f47e7691bef3a8934ebf36af3f15.jpg\" style=\"width: 250.0px;float: right;margin: 0 1.0em 1.0em 1.0em;max-width: 100.0%;max-height: 100.0%;\" /></p><p><em>Hello, Codeforces!</em></p><p><em>We, the <a href=\"https://ton.org/\">TON Foundation</a> team, are pleased to support CodeTON Round 6.</em></p><p><em>The Open Network (TON) is a fully decentralized layer-1 blockchain designed to onboard billions of users to Web3.</em></p><p><em>Since July 2022, <a href=\"/blog/entry/104544\">we have been supporting</a> Codeforces as a title sponsor. This round is another way for us to contribute to the development of the community.</em></p><p><em>The winners of CodeTON Round 6 will receive valuable prizes.</em></p><p><em>The first 1,023 participants will receive prizes in TON cryptocurrency:</em></p> <ul> <li><em>1st place: 1,024 TON</em></li> <li><em>2โ3 places: 512 TON each</em></li> <li><em>4โ7 places: 256 TON each</em></li> <li><em>8โ15 places: 128 TON each</em></li> <li><em>โฆ</em></li> <li><em>512โ1,023 places: 2 TON each</em></li> </ul><p><em>We wish you good luck at CodeTON Round 6 and hope you enjoy the contest!</em></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120458\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1870\" class=\"notice\" style=\"text-decoration: none;\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-223600-121083\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"223600\",\n blogEntryId: \"120458\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+394</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/glebustim\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/glebustim\">\n glebustim\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120458#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120458#comments\">\n 171\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"120865\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120240\"> <p>Codeforces Round #897 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/salyg1n\" title=\"Master salyg1n\" class=\"rated-user user-orange\">salyg1n</a>,\r\n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces! ๐คฏ</p><p><a class=\"rated-user user-red\" href=\"/profile/green_gold_dog\" title=\"Grandmaster green_gold_dog\">green_gold_dog</a>, <a class=\"rated-user user-orange\" href=\"/profile/ace5\" title=\"International Master ace5\">ace5</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> and I <a class=\"rated-user user-orange\" href=\"/profile/salyg1n\" title=\"Master salyg1n\">salyg1n</a> are pleased to invite you to participate in <a href=\"https://codeforces.com/contest/1867\">Codeforces Round 897 (Div. 2)</a>, which will take place on <a href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=11&month=9&year=2023&hour=17&min=35&sec=0&p1=166\">Monday, September 11, 2023 in 17:35</a>.</p><p>This round will be <strong>rated</strong> for participants whose <strong>rating is below 2100</strong>.</p><p>You will be given 6 tasks and 2 hours to solve them. We recommend reading all the tasks. <strong>Interactive tasks may occur in the round</strong>, so we suggest reading this <a href=\"https://codeforces.com/blog/entry/45307\">post</a>.</p><p>We want to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/Aleks5d\" title=\"Grandmaster Aleks5d\">Aleks5d</a> for coordinating the round and improving one of the tasks. ๐ค</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Allvik06\" title=\"International Grandmaster Allvik06\">Allvik06</a>, <a class=\"rated-user user-red\" href=\"/profile/Nutella3000\" title=\"Grandmaster Nutella3000\">Nutella3000</a>, <a class=\"rated-user user-red\" href=\"/profile/arbuzick\" title=\"International Grandmaster arbuzick\">arbuzick</a>, <a class=\"rated-user user-red\" href=\"/profile/alegsandyr\" title=\"Grandmaster alegsandyr\">alegsandyr</a>, <a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/FairyWinx\" title=\"Grandmaster FairyWinx\">FairyWinx</a>, <a class=\"rated-user user-red\" href=\"/profile/zwezdinv\" title=\"Grandmaster zwezdinv\">zwezdinv</a>, <a class=\"rated-user user-orange\" href=\"/profile/valerikk\" title=\"Master valerikk\">valerikk</a>, <a class=\"rated-user user-orange\" href=\"/profile/danya111\" title=\"Master danya111\">danya111</a>, <a class=\"rated-user user-orange\" href=\"/profile/EJIC_B_KEDAX\" title=\"Master EJIC_B_KEDAX\">EJIC_B_KEDAX</a>, <a class=\"rated-user user-orange\" href=\"/profile/dushenkov\" title=\"Master dushenkov\">dushenkov</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/aleksandro\" title=\"Master aleksandro\">aleksandro</a>, <a class=\"rated-user user-orange\" href=\"/profile/Yar_sem\" title=\"Master Yar_sem\">Yar_sem</a>, <a class=\"rated-user user-orange\" href=\"/profile/asafiul\" title=\"Master asafiul\">asafiul</a>, <a class=\"rated-user user-violet\" href=\"/profile/Ivan_len\" title=\"Candidate Master Ivan_len\">Ivan_len</a>, <a class=\"rated-user user-violet\" href=\"/profile/ArtAlex\" title=\"Candidate Master ArtAlex\">ArtAlex</a>, <a class=\"rated-user user-violet\" href=\"/profile/Undying\" title=\"Candidate Master Undying\">Undying</a>, <a class=\"rated-user user-violet\" href=\"/profile/JustNik77\" title=\"Candidate Master JustNik77\">JustNik77</a>, <a class=\"rated-user user-violet\" href=\"/profile/Pavarishko\" title=\"Candidate Master Pavarishko\">Pavarishko</a> and <a class=\"rated-user user-violet\" href=\"/profile/xnor\" title=\"Candidate Master xnor\">xnor</a> for testing the round and giving valuable feedback. ๐ <span style=\"color: rgb(255,255,255);\">orz</span></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/ryskmax\" title=\"Expert ryskmax\">ryskmax</a> for being the only blue tester and giving valuable feedback. ๐ณ </p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/DimaTomsk\" title=\"Master DimaTomsk\">DimaTomsk</a> and <a class=\"rated-user user-orange\" href=\"/profile/ilyakrasnovv\" title=\"Master ilyakrasnovv\">ilyakrasnovv</a> for viewing some of the tasks and giving valuable feedback. ๐ค <span style=\"color: rgb(255,255,255);\"></span></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/stepanov.aa\" title=\"Grandmaster stepanov.aa\">stepanov.aa</a> for <strong>not</strong> testing the round. ๐ฆฅ <span style=\"color: rgb(255,255,255);\">:(</span></p></li> <li><p>The authors of the task <em>5. Overtaking</em> from IOI 2023 for <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> taking a <strong>gold medal</strong>. ๐ฅ <span style=\"color: rgb(255,255,255);\">Too dead? Yes, so am I.</span></p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and <a class=\"rated-user user-admin\" href=\"/profile/geranazavr555\" title=\"Headquarters, geranazavr555\">geranazavr555</a> for the excellent codeforces and polygon platforms. ๐ฆ <span style=\"color: rgb(255,255,255);\">Thank you!</span></p></li> </ul><p>We hope you'll enjoy our problems! Good luck!</p><p><strong>UPD.</strong> Score distribution: $$$500 - 1000 - 1250 - 2000 - (2000 + 1000) - 4000$$$.</p><p><strong>UPD2.</strong> Congratulations to the winners!</p><p><strong>Div. 2</strong></p> <ol> <li><p><a class=\"rated-user user-violet\" href=\"/profile/candidatecandidatemaster\" title=\"Candidate Master candidatecandidatemaster\">candidatecandidatemaster</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Coreopsis\" title=\"Specialist Coreopsis\">Coreopsis</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/iFFT\" title=\"Expert iFFT\">iFFT</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/Dorothy__\" title=\"Expert Dorothy__\">Dorothy__</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/wfoifysaasisufgv\" title=\"Newbie wfoifysaasisufgv\">wfoifysaasisufgv</a></p></li> </ol><p><strong>Div. 1</strong></p> <ol> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/arvindf232\" title=\"Legendary Grandmaster arvindf232\"><span class=\"legendary-user-first-letter\">a</span>rvindf232</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Rubikun\" title=\"International Grandmaster Rubikun\">Rubikun</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Vercingetorix\" title=\"International Grandmaster Vercingetorix\">Vercingetorix</a></p></li> </ol><p><strong>UPD3.</strong> <a href=\"https://codeforces.com/blog/entry/120353\">Editorial.</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120240\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1867\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 897 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230855-120865\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230855\",\n blogEntryId: \"120240\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+280</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/salyg1n\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/salyg1n\">\n salyg1n\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120240#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120240#comments\">\n 218\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n\r\n<div class=\"pagination\">\r\n <ul>\r\n <span class=\"inactive\">←</span>\r\n <li>\r\n <span class=\"page-index active\" pageIndex=\"1\"><a href=\"/page/1\">1</a></span>\r\n </li>\r\n <li>\r\n <span class=\"page-index\" pageIndex=\"2\"><a href=\"/page/2\">2</a></span>\r\n </li>\r\n <li>\r\n <span 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Fish"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fish</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p><span class=\"tex-span\"><i>n</i></span> fish, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, live in a lake. Every day right one pair of fish meet, and the probability of each other pair meeting is the same. If two fish with indexes i and j meet, the first will eat up the second with the probability <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span>, and the second will eat up the first with the probability <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ji</i></sub>โ=โ1โ-โ<i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span>. The described process goes on until there are at least two fish in the lake. For each fish find out the probability that it will survive to be the last in the lake.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ18</span>) โ the amount of fish in the lake. Then there follow <span class=\"tex-span\"><i>n</i></span> lines with <span class=\"tex-span\"><i>n</i></span> real numbers each โ matrix <span class=\"tex-span\"><i>a</i></span>. <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (<span class=\"tex-span\">0โโคโ<i>a</i><sub class=\"lower-index\"><i>ij</i></sub>โโคโ1</span>) โ the probability that fish with index <span class=\"tex-span\"><i>i</i></span> eats up fish with index <span class=\"tex-span\"><i>j</i></span>. It's guaranteed that the main diagonal contains zeros only, and for other elements the following is true: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub>โ=โ1โ-โ<i>a</i><sub class=\"lower-index\"><i>ji</i></sub></span>. All real numbers are given with not more than 6 characters after the decimal point.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>n</i></span> space-separated real numbers accurate to not less than 6 decimal places. Number with index <span class=\"tex-span\"><i>i</i></span> should be equal to the probability that fish with index <span class=\"tex-span\"><i>i</i></span> will survive to be the last in the lake.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>0 0.5<br/>0.5 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0.500000 0.500000 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>0 1 1 1 1<br/>0 0 0.5 0.5 0.5<br/>0 0.5 0 0.5 0.5<br/>0 0.5 0.5 0 0.5<br/>0 0.5 0.5 0.5 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1.000000 0.000000 0.000000 0.000000 0.000000 </pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"4e8f50ae636c4dd5f2b66b618d2bc10a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"09c09aef8ad5be2498175d65869f04dcf51f7d0b\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/16\">Codeforces Beta Round 16 (Div. 2 Only)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/16/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Bitmasks\">\r\n bitmasks\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Probabilities, expected values, statistics, random variables, etc\">\r\n probabilities\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n 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class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_1cacc5ef9f09f380a0102b803976ca899346c2ed\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fish</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p><span class=\"tex-span\"><i>n</i></span> fish, numbered from <span class=\"tex-span\">1</span> to <span class=\"tex-span\"><i>n</i></span>, live in a lake. Every day right one pair of fish meet, and the probability of each other pair meeting is the same. If two fish with indexes i and j meet, the first will eat up the second with the probability <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span>, and the second will eat up the first with the probability <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ji</i></sub>โ=โ1โ-โ<i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span>. The described process goes on until there are at least two fish in the lake. For each fish find out the probability that it will survive to be the last in the lake.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ18</span>) โ the amount of fish in the lake. Then there follow <span class=\"tex-span\"><i>n</i></span> lines with <span class=\"tex-span\"><i>n</i></span> real numbers each โ matrix <span class=\"tex-span\"><i>a</i></span>. <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub></span> (<span class=\"tex-span\">0โโคโ<i>a</i><sub class=\"lower-index\"><i>ij</i></sub>โโคโ1</span>) โ the probability that fish with index <span class=\"tex-span\"><i>i</i></span> eats up fish with index <span class=\"tex-span\"><i>j</i></span>. It's guaranteed that the main diagonal contains zeros only, and for other elements the following is true: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>ij</i></sub>โ=โ1โ-โ<i>a</i><sub class=\"lower-index\"><i>ji</i></sub></span>. All real numbers are given with not more than 6 characters after the decimal point.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>n</i></span> space-separated real numbers accurate to not less than 6 decimal places. Number with index <span class=\"tex-span\"><i>i</i></span> should be equal to the probability that fish with index <span class=\"tex-span\"><i>i</i></span> will survive to be the last in the lake.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />0 0.5<br />0.5 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0.500000 0.500000 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />0 1 1 1 1<br />0 0 0.5 0.5 0.5<br />0 0.5 0 0.5 0.5<br />0 0.5 0.5 0 0.5<br />0 0.5 0.5 0.5 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1.000000 0.000000 0.000000 0.000000 0.000000 </pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='2e03790445a5a5b0be02ccd5f8aaf33e'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 โ Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121650\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/121025\"> <p>Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a>,\r\n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><img alt=\"logo\" src=\"/predownloaded/e3/33/e333915aebea955b43b4ad17845f6dbf58875a0c.png\" style=\"float: right;height: 100.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></p><p>Sugeng enjing, <strong>Codeforces</strong>! ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ</p><p>COMPFEST 15 is happy to invite you to participate in <a href=\"/contest/1876\" title=\"Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 1, based on COMPFEST 15 - Final Round)</a> and <a href=\"/contest/1877\" title=\"Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)\">Codeforces Round (Div. 2, based on COMPFEST 15 - Final Round)</a> on <a class=\"contest-time\" contestid=\"1876\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=8&month=10&year=2023&hour=12&min=5&sec=0&p1=166\"><span class=\"format-time-with-dow\">Oct/08/2023 12:05 (Moscow time)</span></a>. Both rounds will be <strong>rated</strong>. You will be given <strong>2 hours and 30 minutes</strong> to solve <strong>7 problems</strong>.</p><h2><strong>Note the unusual time of the round</strong>.</h2><p>The problems are written by <a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-red\" href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\">Pyqe</a>, and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a>.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-legendary\" href=\"/profile/KAN\" title=\"Legendary Grandmaster KAN\"><span class=\"legendary-user-first-letter\">K</span>AN</a> for helping to host the round;</li> <li><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> and <a class=\"rated-user user-orange\" href=\"/profile/ScarletS\" title=\"Master ScarletS\">ScarletS</a> for the based coordination;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/gansixeneh\" title=\"Candidate Master gansixeneh\">gansixeneh</a> and <a class=\"rated-user user-violet\" href=\"/profile/nandonathaniel\" title=\"Candidate Master nandonathaniel\">nandonathaniel</a> for helping with the problem preparation;</li> <li><a class=\"rated-user user-violet\" href=\"/profile/ArvinCiu\" title=\"Candidate Master ArvinCiu\">ArvinCiu</a>, <a class=\"rated-user user-blue\" href=\"/profile/CyberSleeper\" title=\"Expert CyberSleeper\">CyberSleeper</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Edbert.H\" title=\"Expert Edbert.H\">Edbert.H</a> for providing alternate solutions in the early stages;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for writing the Russian translations;</li> <li><a class=\"rated-user user-orange\" href=\"/profile/Aaeria\" title=\"Master Aaeria\">Aaeria</a>, <a class=\"rated-user user-blue\" href=\"/profile/AMnu\" title=\"Expert AMnu\">AMnu</a>, <a class=\"rated-user user-orange\" href=\"/profile/Berted\" title=\"Master Berted\">Berted</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-cyan\" href=\"/profile/buffering\" title=\"Specialist buffering\">buffering</a>, <a class=\"rated-user user-orange\" href=\"/profile/Drew_\" title=\"Master Drew_\">Drew_</a>, <a class=\"rated-user user-legendary\" href=\"/profile/dorijanlendvaj\" title=\"Legendary Grandmaster dorijanlendvaj\"><span class=\"legendary-user-first-letter\">d</span>orijanlendvaj</a>, <a class=\"rated-user user-orange\" href=\"/profile/eggag32\" title=\"Master eggag32\">eggag32</a>, <a class=\"rated-user user-violet\" href=\"/profile/Elben85\" title=\"Candidate Master Elben85\">Elben85</a>, <a class=\"rated-user user-red\" href=\"/profile/emorgan5289\" title=\"International Grandmaster emorgan5289\">emorgan5289</a>, <a class=\"rated-user user-orange\" href=\"/profile/faustaadp\" title=\"Master faustaadp\">faustaadp</a>, <a class=\"rated-user user-red\" href=\"/profile/ffao\" title=\"International Grandmaster ffao\">ffao</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-legendary\" href=\"/profile/gamegame\" title=\"Legendary Grandmaster gamegame\"><span class=\"legendary-user-first-letter\">g</span>amegame</a>, <a class=\"rated-user user-violet\" href=\"/profile/hocky\" title=\"Candidate Master hocky\">hocky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Insta-x\" title=\"Expert Insta-x\">Insta-x</a>, <a class=\"rated-user user-red\" href=\"/profile/jdurie\" title=\"Grandmaster jdurie\">jdurie</a>, <a class=\"rated-user user-orange\" href=\"/profile/joelgun14\" title=\"Master joelgun14\">joelgun14</a>, <a class=\"rated-user user-violet\" href=\"/profile/KerakTelor\" title=\"Candidate Master KerakTelor\">KerakTelor</a>, <a class=\"rated-user user-blue\" href=\"/profile/Marky\" title=\"Expert Marky\">Marky</a>, <a class=\"rated-user user-blue\" href=\"/profile/Murinh0\" title=\"Expert Murinh0\">Murinh0</a>, <a class=\"rated-user user-red\" href=\"/profile/nvmdava\" title=\"Grandmaster nvmdava\">nvmdava</a>, <a class=\"rated-user user-orange\" href=\"/profile/nyab\" title=\"Master nyab\">nyab</a>, <a class=\"rated-user user-orange\" href=\"/profile/Owmicron\" title=\"Master Owmicron\">Owmicron</a>, <a class=\"rated-user user-red\" href=\"/profile/prvocislo\" title=\"Grandmaster prvocislo\">prvocislo</a>, <a class=\"rated-user user-red\" href=\"/profile/PurpleCrayon\" title=\"International Grandmaster PurpleCrayon\">PurpleCrayon</a>, <a class=\"rated-user user-red\" href=\"/profile/rama_pang\" title=\"Grandmaster rama_pang\">rama_pang</a>, <a class=\"rated-user user-blue\" href=\"/profile/TakeMe\" title=\"Expert TakeMe\">TakeMe</a>, <a class=\"rated-user user-blue\" href=\"/profile/sahil_k\" title=\"Expert sahil_k\">sahil_k</a>, <a class=\"rated-user user-red\" href=\"/profile/user202729_\" title=\"International Grandmaster user202729_\">user202729_</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-green\" href=\"/profile/WHCPP\" title=\"Pupil WHCPP\">WHCPP</a>, and <a class=\"rated-user user-violet\" href=\"/profile/ZeroScar\" title=\"Candidate Master ZeroScar\">ZeroScar</a> for testing the contest and providing us very useful feedback;</li> <li>Universitas Indonesia, all the local committees, administrators, and managers of the whole COMPFEST event;</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Codeforces and Polygon platform!</li> </ul><p>COMPFEST itself is an annual event hosted by Universitas Indonesia. It is the largest student-run IT event in Indonesia and competitive programming contest is one of the competitions hosted.</p><p>We hope you will enjoy and have fun in the contest. Muga-muga beja lan isa entuk biji apik!! ๐ช๐ช๐ฅ๐ฅ</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121025\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1876\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1877\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-118490-121650\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"118490\",\n blogEntryId: \"121025\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121650\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+359</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121650\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n <div style=\"position: relative; float: left; left: -1.5rem; top: 1rem;\">\r\n\n<style data-nocturne=\"true\" type=\"text/css\">\n.ComplaintFrame {\n display: inline-block;\n position: absolute;\n top: 0;\n right: -1.4em;\n}\n.ComplaintFrame a {\n text-decoration: none;\n color: #ff8c00;\n opacity: 0.5;\n}\n.ComplaintFrame a:hover {\n opacity: 1;\n}\n._ComplaintFrame_popup p,\n._ComplaintFrame_popup button {\n margin-top: 1rem;\n}\n._ComplaintFrame_popup input[type=submit] {\n padding: 0.25rem 2rem;\n}\n._ComplaintFrame_popup ul {\n margin-top: 1em !important;\n margin-bottom: 1em !important;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n $(\".ComplaintFrame a\").click(function () {\n const $complaintFrame = $(this).closest(\".ComplaintFrame\");\n const targetId = $complaintFrame.attr(\"data-targetId\");\n const targetClass = $complaintFrame.attr(\"data-targetClass\");\n\n Codeforces.facebox(\"._ComplaintFrame_popup\", \"//codeforces.org/s/81027\");\n\n $.post(\"/data/complaint\", {\n action: \"findComplaintReasons\",\n targetClass: $complaintFrame.attr(\"data-targetClass\"),\n targetId: $complaintFrame.attr(\"data-targetId\")\n }, function (response) {\n if (response.success === \"true\") {\n const complaintReasons = response.complaintReasons;\n const complaint = response.complaint;\n\n const $popup = $(\"#facebox ._ComplaintFrame_popup\");\n for (const complaintReason of complaintReasons) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", complaintReason.id);\n $li.find(\"span\")\n .html(getLocalizedName(complaintReason)\n + \" <i class=\\\"icon-question-sign clickable-title\\\" title=\\\"\"\n + getLocalizedDescription(complaintReason)\n + \"\\\"></i>\")\n .attr(\"title\", getLocalizedDescription(complaintReason));\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n if (complaint && complaint.complaintReasonId === complaintReason.id) {\n $li.find(\"input[name=complaintReasonId]\").attr(\"checked\", \"checked\");\n }\n $li.find(\".clickable-title\").click(function () {\n alert(getLocalizedDescription(complaintReason));\n return false;\n }).css(\"position\", \"relative\").css(\"bottom\", \"1px\").css(\"font-size\", \"12px\");\n }\n\n if (complaint) {\n let $li = $(\"#facebox ._ComplaintFrame_complaintReasonItemProto li\").clone();\n $li.find(\"input[name=complaintReasonId]\").attr(\"value\", 0);\n $li.find(\"span\").html(\"Delete complaint\");\n $li.show();\n $li.appendTo($popup.find(\"ul\"));\n }\n\n $popup.find(\"._ComplaintFrame_submitForm\").submit(function () {\n const complaintReasonId = $popup.find(\"input[name=complaintReasonId]:checked\").val();\n if (complaintReasonId === undefined) {\n alert(\"Please select complaint reason\");\n return false;\n }\n\n $.post(\"/data/complaint\", {\n action: \"newComplaint\",\n targetClass: targetClass,\n targetId: targetId,\n complaintReasonId: complaintReasonId\n }, function (response) {\n if (response.success === \"true\") {\n Codeforces.showMessage(\"Complaint has been created\");\n $.facebox.close();\n }\n }, \"json\");\n\n return false;\n });\n }\n }, \"json\");\n\n return false;\n });\n}); </script>\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Pyqe\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Pyqe\">\n Pyqe\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/03/2023 12:02\">4 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121025#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121025#comments\">\n 41\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n <script>\r\n function adjustTopicComplainFrames() {\r\n let topicIds = [];\r\n\r\n $(\".has-topic-id\").each(function () {\r\n const $this = $(this);\r\n const topicId = $this.attr(\"topicId\");\r\n if (topicId) {\r\n topicIds.push(topicId);\r\n }\r\n });\r\n\r\n $.post(\"/data/topics\", {\r\n action: \"findComplainableTopicIds\",\r\n topicIds: topicIds.join(\",\")\r\n }, function (json) {\r\n if (json[\"success\"] === \"true\") {\r\n for (const topicId of json[\"complainableTopicIds\"].split(\",\")) {\r\n $(\".has-topic-id[topicId=\" + topicId + \"]\").each(function () {\r\n $(this).find(\".meta .ComplaintFrame\").css(\"display\", \"inline-block\");\r\n });\r\n }\r\n }\r\n }, \"json\");\r\n }\r\n\r\n $(function () {\r\n adjustTopicComplainFrames();\r\n })\r\n </script>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121650\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121650, _tta: Codeforces.tta(), topicRevisionId: 322530, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121739\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/121114\"> <p>Codeforces Command Lines (2023-10-06)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\" class=\"rated-user user-blue\">Vladosiya</a>,\r\n <a href=\"/topic/121739/en7\">history</a>,\r\n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>We've compiled a list of command lines that Codeforces uses to compile and run solutions in various languages and compilers.</p><p>It is up-to-date as of today (2023-10-06), and we will make efforts to keep it current in the future, but this is not guaranteed.</p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/121114\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-73866-121739\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"73866\",\n blogEntryId: \"121114\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compilers\" class=\"tag notice\" style=\"text-decoration: none;\">compilers</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=compiler+options\" class=\"tag notice\" style=\"text-decoration: none;\">compiler options</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=languages\" class=\"tag notice\" style=\"text-decoration: none;\">languages</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+235</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121739\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n <div style=\"position: relative; float: left; left: -1.5rem; top: 1rem;\">\r\n\n\n\n </div>\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/Vladosiya\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/Vladosiya\">\n Vladosiya\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Oct/06/2023 11:44\">34 hours ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/121114#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/121114#comments\">\n 8\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121739\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121739, _tta: Codeforces.tta(), topicRevisionId: 322579, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121449\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120824\"> <p>Codeforces Round 901 (Div. 1, Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a>,\r\n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I'm pleased to invite you to <a href=\"/contest/1874\" title=\"Codeforces Round 901 (Div. 1)\">Codeforces Round 901 (Div. 1)</a> and <a href=\"/contest/1875\" title=\"Codeforces Round 901 (Div. 2)\">Codeforces Round 901 (Div. 2)</a>. It starts on <a class=\"contest-time\" contestid=\"1874\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=30&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/30/2023 17:35 (Moscow time)</span></a>. It also means, the National Day of China arrives during the round. Wish you a nice vacation! ๐๐๐</p><p>For both divisions, you will have <strong>3 hours</strong> to solve <strong>7 problems</strong>.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his wonderful coordination.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a> for Russian translation and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for helping us with Russian clarifications.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\">GeZhiyuan</a> for providing all the problems and "a few" rejected problems.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> and <a class=\"rated-user user-red\" href=\"/profile/SanweiTreap\" title=\"Grandmaster SanweiTreap\">SanweiTreap</a> for helping me prepare the problems.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a>, <a class=\"rated-user user-legendary\" href=\"/profile/wangziji\" title=\"Legendary Grandmaster wangziji\"><span class=\"legendary-user-first-letter\">w</span>angziji</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a>, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> and <a class=\"rated-user user-legendary\" href=\"/profile/flowerletter\" title=\"Legendary Grandmaster flowerletter\"><span class=\"legendary-user-first-letter\">f</span>lowerletter</a> for Legendary Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/sjcsjcsjc\" title=\"International Grandmaster sjcsjcsjc\">sjcsjcsjc</a>, <a class=\"rated-user user-red\" href=\"/profile/He_Ren\" title=\"International Grandmaster He_Ren\">He_Ren</a>, <a class=\"rated-user user-red\" href=\"/profile/GaryZ005\" title=\"International Grandmaster GaryZ005\">GaryZ005</a>, <a class=\"rated-user user-red\" href=\"/profile/platelet\" title=\"International Grandmaster platelet\">platelet</a>, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a>, <a class=\"rated-user user-red\" href=\"/profile/thenymphsofdelphi\" title=\"International Grandmaster thenymphsofdelphi\">thenymphsofdelphi</a>, <a class=\"rated-user user-red\" href=\"/profile/DerekFeng\" title=\"International Grandmaster DerekFeng\">DerekFeng</a>, <a class=\"rated-user user-red\" href=\"/profile/Juanzhang\" title=\"International Grandmaster Juanzhang\">Juanzhang</a> and <a class=\"rated-user user-red\" href=\"/profile/ttklwxx\" title=\"International Grandmaster ttklwxx\">ttklwxx</a> for International Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/juju527\" title=\"Grandmaster juju527\">juju527</a>, <a class=\"rated-user user-red\" href=\"/profile/zimpha\" title=\"Grandmaster zimpha\">zimpha</a>, <a class=\"rated-user user-red\" href=\"/profile/765\" title=\"Grandmaster 765\">765</a>, <a class=\"rated-user user-red\" href=\"/profile/xuanquang1999\" title=\"Grandmaster xuanquang1999\">xuanquang1999</a>, <a class=\"rated-user user-red\" href=\"/profile/CrTsIr\" title=\"Grandmaster CrTsIr\">CrTsIr</a> and <a class=\"rated-user user-red\" href=\"/profile/EasonTAO\" title=\"Grandmaster EasonTAO\">EasonTAO</a> for Grandmaster Testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/SATSKY\" title=\"Master SATSKY\">SATSKY</a>, <a class=\"rated-user user-orange\" href=\"/profile/lanhf\" title=\"Master lanhf\">lanhf</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hank2019\" title=\"Master Hank2019\">Hank2019</a> and <a class=\"rated-user user-orange\" href=\"/profile/Yakumo_Ran\" title=\"Master Yakumo_Ran\">Yakumo_Ran</a> for Master Testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/DaniraSilla\" title=\"Candidate Master DaniraSilla\">DaniraSilla</a> and <a class=\"rated-user user-violet\" href=\"/profile/kriepiekrollie\" title=\"Candidate Master kriepiekrollie\">kriepiekrollie</a> for Candidate Master Testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/raulandreipop\" title=\"Expert raulandreipop\">raulandreipop</a>, <a class=\"rated-user user-blue\" href=\"/profile/micho\" title=\"Expert micho\">micho</a>, <a class=\"rated-user user-blue\" href=\"/profile/alwyn\" title=\"Expert alwyn\">alwyn</a>, <a class=\"rated-user user-blue\" href=\"/profile/ArgintLaAnu\" title=\"Expert ArgintLaAnu\">ArgintLaAnu</a>, <a class=\"rated-user user-blue\" href=\"/profile/IssamOtoz\" title=\"Expert IssamOtoz\">IssamOtoz</a> and <a class=\"rated-user user-blue\" href=\"/profile/jakao\" title=\"Expert jakao\">jakao</a> for Expert Testing.</p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/CLown1331\" title=\"Pupil CLown1331\">CLown1331</a> for Pupil Testing.</p></li> <li><p>You for participating the round.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</p></li> </ul><p>Especially, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/errorgorn\" title=\"International Grandmaster errorgorn\">errorgorn</a> for his great contribution to the round, <a class=\"rated-user user-red\" href=\"/profile/njwrz\" title=\"International Grandmaster njwrz\">njwrz</a> for providing user solutions for all the problems, <a class=\"rated-user user-legendary\" href=\"/profile/Kevin114514\" title=\"Legendary Grandmaster Kevin114514\"><span class=\"legendary-user-first-letter\">K</span>evin114514</a> for making the announcement and tutorial more readable.</p><p>Finally and most importantly, I would like to thank <a class=\"rated-user user-red\" href=\"/profile/znstz2018\" title=\"Grandmaster znstz2018\">znstz2018</a> for helping me with everything patiently all the time. This round can't happen without him.</p><p>The main character of the problems will be Jellyfish, a sweet little girl. ๐๐๐</p><p>Score distribution:</p> <ul> <li><p>Div.1: $$$500$$$ โ $$$1250$$$ โ $$$1500$$$ โ $$$2250$$$ โ $$$3000$$$ โ $$$4000$$$ โ $$$5000$$$</p></li> <li><p>Div.2: $$$500$$$ โ $$$1000$$$ โ $$$1000$$$ โ $$$1250$$$ โ $$$2000$$$ โ $$$2250$$$ โ $$$3000$$$</p></li> </ul><p>Good Luck & Have Fun! ๐ฅ๐ฅ๐ฅ</p><p><strong>UPD1:</strong> <a href=\"https://codeforces.com/blog/entry/120943\">Editorial</a> is out.</p><p><strong>UPD2:</strong> Congratulations to the winners!</p> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\"><span class=\"legendary-user-first-letter\">B</span>enq</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Qingyu\" title=\"International Grandmaster Qingyu\">Qingyu</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/amiya\" title=\"Legendary Grandmaster amiya\"><span class=\"legendary-user-first-letter\">a</span>miya</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><ol> <li><p><a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/RollingPanda\" title=\"Newbie RollingPanda\">RollingPanda</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/WanYuanShenWanDe\" title=\"Newbie WanYuanShenWanDe\">WanYuanShenWanDe</a></p></li> </ol></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.1</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-red\" href=\"/profile/H_stove\" title=\"Grandmaster H_stove\">H_stove</a></p><p>B. <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>C. <a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></p><p>D. <a class=\"rated-user user-red\" href=\"/profile/ooOAM\" title=\"Grandmaster ooOAM\">ooOAM</a></p><p>E. <a class=\"rated-user user-orange\" href=\"/profile/Salley-Garden\" title=\"Master Salley-Garden\">Salley-Garden</a></p><p>F. <a class=\"rated-user user-red\" href=\"/profile/i_will_be_less_than_blue\" title=\"Grandmaster i_will_be_less_than_blue\">i_will_be_less_than_blue</a></p><p>G. <a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a> (after the contest)</p></div></div> <div class=\"spoiler\"><b class=\"spoiler-title\">first solves in Div.2</b><div class=\"spoiler-content\" style=\"display: none;\"><p>A. <a class=\"rated-user user-blue\" href=\"/profile/Azaml\" title=\"Expert Azaml\">Azaml</a></p><p>B. <a class=\"rated-user user-blue\" href=\"/profile/Shirotsume\" title=\"Expert Shirotsume\">Shirotsume</a></p><p>C. <a class=\"rated-user user-gray\" href=\"/profile/viveksingh912\" title=\"Newbie viveksingh912\">viveksingh912</a></p><p>D. <a class=\"rated-user user-gray\" href=\"/profile/kaiboy\" title=\"Newbie kaiboy\">kaiboy</a></p><p>E. <a class=\"rated-user user-cyan\" href=\"/profile/FlyBell\" title=\"Specialist FlyBell\">FlyBell</a></p><p>F. <a class=\"rated-user user-black\" href=\"/profile/Rapturelike\" title=\"Unrated, Rapturelike\">Rapturelike</a></p><p>G. <a class=\"rated-user user-blue\" href=\"/profile/rainboy\" title=\"Expert rainboy\">rainboy</a></p></div></div></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120824\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1874\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 1)</a> </span>\r\n </div>\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1875\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 901 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-238039-121449\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"238039\",\n blogEntryId: \"120824\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+165</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121449\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/GeZhiyuan\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/GeZhiyuan\">\n GeZhiyuan\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/27/2023 09:25\">11 days ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120824#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120824#comments\">\n 231\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121449\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121449, _tta: Codeforces.tta(), topicRevisionId: 322013, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121303\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120678\"> <p>Codeforces Round #900 (Div. 3)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/AlphaMale06\" title=\"Specialist AlphaMale06\" class=\"rated-user user-cyan\">AlphaMale06</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p><a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a> and I are glad to invite you to the <a href=\"/contest/1878\" title=\"Codeforces Round 900 (Div. 3)\">Codeforces Round 900 (Div. 3)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1878\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=26&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/26/2023 17:35 (Moscow time)</span></a></p><p>You will be given <strong>7 problems</strong> and <strong>2 hours and 15 minutes</strong> to solve them.</p><p>Note that the <strong>penalty</strong> for the wrong submission in this round is <strong>10 minutes</strong>.</p><p>Also note that there will be a <strong>12 hour open hacking phase</strong> after the round.</p><p><a href=\"https://codeforces.com/blog/entry/59228\">Remember</a>, that only the <em>trusted participants of the third division</em> will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a <em>trusted participant of the third division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them)</li> <li>do not have a point of 1900 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, the round will be rated for you.</strong></p><p>Problems have been created and prepared by <a class=\"rated-user user-blue\" href=\"/profile/AlphaMale06\" title=\"Expert AlphaMale06\">AlphaMale06</a>, <a class=\"rated-user user-green\" href=\"/profile/ognjentesic\" title=\"Pupil ognjentesic\">ognjentesic</a>, <a class=\"rated-user user-orange\" href=\"/profile/wxhtzdy\" title=\"Master wxhtzdy\">wxhtzdy</a>, <a class=\"rated-user user-cyan\" href=\"/profile/OAleksa\" title=\"Specialist OAleksa\">OAleksa</a>, <a class=\"rated-user user-cyan\" href=\"/profile/AndrewPav\" title=\"Specialist AndrewPav\">AndrewPav</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Acanikolic73\" title=\"Specialist Acanikolic73\">Acanikolic73</a>, and <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>.</p><p>We would also to thank:</p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a> for the amazing coordination and help with preparing a balanced problemset, and for giving us the opportunity to create a Div. 3 round.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for the amazing Polygon and Codeforces platforms.</li> <li><a class=\"rated-user user-red\" href=\"/profile/JovanB\" title=\"Grandmaster JovanB\">JovanB</a>, <a class=\"rated-user user-red\" href=\"/profile/abc864197532\" title=\"International Grandmaster abc864197532\">abc864197532</a>, <a class=\"rated-user user-red\" href=\"/profile/sevlll777\" title=\"Grandmaster sevlll777\">sevlll777</a> for red testing</li> <li><a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>, <a class=\"rated-user user-orange\" href=\"/profile/n0sk1ll\" title=\"Master n0sk1ll\">n0sk1ll</a>, <a class=\"rated-user user-orange\" href=\"/profile/allllekssssa\" title=\"Master allllekssssa\">allllekssssa</a>, <a class=\"rated-user user-orange\" href=\"/profile/Alexdat2000\" title=\"Master Alexdat2000\">Alexdat2000</a>, <a class=\"rated-user user-orange\" href=\"/profile/misorin\" title=\"International Master misorin\">misorin</a>, <a class=\"rated-user user-orange\" href=\"/profile/Hyperbolic\" title=\"International Master Hyperbolic\">Hyperbolic</a> for yellow testing</li> <li><a class=\"rated-user user-violet\" href=\"/profile/DAleksa\" title=\"Candidate Master DAleksa\">DAleksa</a>, <a class=\"rated-user user-violet\" href=\"/profile/ljuba\" title=\"Candidate Master ljuba\">ljuba</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex.kudryashov\" title=\"Candidate Master alex.kudryashov\">alex.kudryashov</a> for purple testing</li> <li><a class=\"rated-user user-blue\" href=\"/profile/MihailoT\" title=\"Expert MihailoT\">MihailoT</a>, <a class=\"rated-user user-blue\" href=\"/profile/SashaT9\" title=\"Expert SashaT9\">SashaT9</a>, <a class=\"rated-user user-blue\" href=\"/profile/ELDRVD\" title=\"Expert ELDRVD\">ELDRVD</a>, <a class=\"rated-user user-blue\" href=\"/profile/Chrisedyong\" title=\"Expert Chrisedyong\">Chrisedyong</a>, <a class=\"rated-user user-blue\" href=\"/profile/tryptophan\" title=\"Expert tryptophan\">tryptophan</a> for blue testing</li> <li><a class=\"rated-user user-cyan\" href=\"/profile/Andrijanikolic73\" title=\"Specialist Andrijanikolic73\">Andrijanikolic73</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Mihajlo18\" title=\"Specialist Mihajlo18\">Mihajlo18</a>, <a class=\"rated-user user-cyan\" href=\"/profile/UrosNedic\" title=\"Specialist UrosNedic\">UrosNedic</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Klaus26\" title=\"Specialist Klaus26\">Klaus26</a>, <a class=\"rated-user user-cyan\" href=\"/profile/Escaquejant\" title=\"Specialist Escaquejant\">Escaquejant</a>, <a class=\"rated-user user-cyan\" href=\"/profile/smax294\" title=\"Specialist smax294\">smax294</a>, <a class=\"rated-user user-cyan\" href=\"/profile/max0n\" title=\"Specialist max0n\">max0n</a> for cyan testing</li> <li><a class=\"rated-user user-gray\" href=\"/profile/Budimmm\" title=\"Newbie Budimmm\">Budimmm</a> for gray testing</li> </ol><p>Also a very special thanks to the most dedicated tester I have ever seen, <a class=\"rated-user user-orange\" href=\"/profile/NemanjaSo2005\" title=\"Master NemanjaSo2005\">NemanjaSo2005</a>.</p><p>I wish you luck, and hope you like the problems and learn from them.</p><p>Update: <a href=\"https://codeforces.com/blog/entry/120813\">Editorial</a> is out.</p><p>Congratulations to the winners:</p><p>Unofficial:</p> <ol> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/SSerxhs\" title=\"International Grandmaster SSerxhs\">SSerxhs</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/neal\" title=\"Legendary Grandmaster neal\"><span class=\"legendary-user-first-letter\">n</span>eal</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/risujiroh\" title=\"International Grandmaster risujiroh\">risujiroh</a></p></li> </ol><p>Official:</p> <ol> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/hackerjohn\" title=\"Specialist hackerjohn\">hackerjohn</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/wahb\" title=\"Specialist wahb\">wahb</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/kutcoder\" title=\"Specialist kutcoder\">kutcoder</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Sxy_Limit\" title=\"Specialist Sxy_Limit\">Sxy_Limit</a></p></li> <li><p><a class=\"rated-user user-green\" href=\"/profile/not_rainboy\" title=\"Pupil not_rainboy\">not_rainboy</a></p></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120678\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1878\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 900 (Div. 3)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-269459-121303\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"269459\",\n blogEntryId: \"120678\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+192</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121303\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/AlphaMale06\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/AlphaMale06\">\n AlphaMale06\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 01:09\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120678#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120678#comments\">\n 347\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121303\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121303, _tta: Codeforces.tta(), topicRevisionId: 321614, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121269\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120644\"> <p>Codeforces Round 899 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a>,\r\n <a href=\"/topic/121269/en9\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces!</p><p>I am pleased to invite you to participate in <a href=\"/contest/1882\" title=\"Codeforces Round 899 (Div. 2)\">Codeforces Round 899 (Div. 2)</a>, which will be held on <a class=\"contest-time\" contestid=\"1882\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=25&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/25/2023 17:35 (Moscow time)</span></a>.</p><p>All problems were written and prepared by me.</p><p>You will be given <strong>5 problems, and one of them is divided into two subtasks</strong>. You will have <strong>2 hours</strong> to solve them.</p><p>I would like to thank:</p> <ul> <li><p><a class=\"rated-user user-orange\" href=\"/profile/irkstepanov\" title=\"International Master irkstepanov\">irkstepanov</a> for excellent coordination and Russian translation!</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for providing useful feedbacks.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a> for helping me much with one problem of the contest.</p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/ko_osaga\" title=\"Legendary Grandmaster ko_osaga\"><span class=\"legendary-user-first-letter\">k</span>o_osaga</a> for Nutella testing.</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/leinad2\" title=\"Grandmaster leinad2\">leinad2</a>, <a class=\"rated-user user-red\" href=\"/profile/Numbering\" title=\"Grandmaster Numbering\">Numbering</a>, <a class=\"rated-user user-red\" href=\"/profile/qwerasdfzxcl\" title=\"International Grandmaster qwerasdfzxcl\">qwerasdfzxcl</a>, <a class=\"rated-user user-red\" href=\"/profile/kizen\" title=\"Grandmaster kizen\">kizen</a>, <a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a> for Red testing.</p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/Kaling\" title=\"Master Kaling\">Kaling</a>, <a class=\"rated-user user-orange\" href=\"/profile/Mingyu331\" title=\"Master Mingyu331\">Mingyu331</a>, <a class=\"rated-user user-orange\" href=\"/profile/chaeyihwan\" title=\"International Master chaeyihwan\">chaeyihwan</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kawaii2DIdolOfGSHS\" title=\"International Master Kawaii2DIdolOfGSHS\">Kawaii2DIdolOfGSHS</a>, <a class=\"rated-user user-orange\" href=\"/profile/azberjibiou\" title=\"International Master azberjibiou\">azberjibiou</a>, <a class=\"rated-user user-orange\" href=\"/profile/mjhmjh1104\" title=\"Master mjhmjh1104\">mjhmjh1104</a>, <a class=\"rated-user user-orange\" href=\"/profile/DELTARUNE\" title=\"Master DELTARUNE\">DELTARUNE</a>, <a class=\"rated-user user-orange\" href=\"/profile/wuhudsm\" title=\"Master wuhudsm\">wuhudsm</a>, <a class=\"rated-user user-orange\" href=\"/profile/hypergraph_coloring\" title=\"International Master hypergraph_coloring\">hypergraph_coloring</a> for Orange testing.</p></li> <li><p><a class=\"rated-user user-violet\" href=\"/profile/unordered_map\" title=\"Candidate Master unordered_map\">unordered_map</a>, <a class=\"rated-user user-violet\" href=\"/profile/alex0211\" title=\"Candidate Master alex0211\">alex0211</a>, <a class=\"rated-user user-violet\" href=\"/profile/gs20036\" title=\"Candidate Master gs20036\">gs20036</a>, <a class=\"rated-user user-violet\" href=\"/profile/namolbbaemi\" title=\"Candidate Master namolbbaemi\">namolbbaemi</a>, <a class=\"rated-user user-violet\" href=\"/profile/eeeDA\" title=\"Candidate Master eeeDA\">eeeDA</a>, <a class=\"rated-user user-violet\" href=\"/profile/nlog\" title=\"Candidate Master nlog\">nlog</a> for Purple testing.</p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/andyandy\" title=\"Expert andyandy\">andyandy</a>, <a class=\"rated-user user-blue\" href=\"/profile/JaewonOh\" title=\"Expert JaewonOh\">JaewonOh</a>, <a class=\"rated-user user-blue\" href=\"/profile/KongUm\" title=\"Expert KongUm\">KongUm</a>, <a class=\"rated-user user-blue\" href=\"/profile/Coruncanius\" title=\"Expert Coruncanius\">Coruncanius</a>, <a class=\"rated-user user-blue\" href=\"/profile/ez_code\" title=\"Expert ez_code\">ez_code</a>, <a class=\"rated-user user-blue\" href=\"/profile/fs_edge\" title=\"Expert fs_edge\">fs_edge</a>, <a class=\"rated-user user-blue\" href=\"/profile/chromate00\" title=\"Expert chromate00\">chromate00</a> for Blue testing.</p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/Hanlana18\" title=\"Newbie Hanlana18\">Hanlana18</a>, <a class=\"rated-user user-gray\" href=\"/profile/papergundam\" title=\"Newbie papergundam\">papergundam</a>, <a class=\"rated-user user-gray\" href=\"/profile/sjmjys954646\" title=\"Newbie sjmjys954646\">sjmjys954646</a> for Gray testing.</p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for great Polygon and Codeforces platforms!</p></li> <li><p>And last but not least, <a class=\"rated-user user-legendary\" href=\"https://codeforces.com/profile/\">You</a> for participating in the round!</p></li> </ul><p>Score distribution: $$$500 - 1000 - 1500 - 2000 - (2000 + 2000)$$$</p><p>Good luck and enjoy the round!</p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120792\">Editorial</a> is out. </p><p><strong>UPD2</strong>: Congratulations to the winners!</p><p><strong>Official Contestants</strong></p> <ol> <li><a class=\"rated-user user-blue\" href=\"/profile/Lycorisqwq\" title=\"Expert Lycorisqwq\">Lycorisqwq</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/zepto\" title=\"Unrated, zepto\">zepto</a></li> <li><a class=\"rated-user user-black\" href=\"/profile/vjudge39\" title=\"Unrated, vjudge39\">vjudge39</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/Beelzebub_blue\" title=\"Candidate Master Beelzebub_blue\">Beelzebub_blue</a></li> <li><a class=\"rated-user user-violet\" href=\"/profile/_t_W_\" title=\"Candidate Master _t_W_\">_t_W_</a></li> </ol><p><strong>Official + Unofficial Contestants</strong></p> <ol> <li><a class=\"rated-user user-red\" href=\"/profile/ksun48\" title=\"International Grandmaster ksun48\">ksun48</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/antontrygubO_o\" title=\"International Grandmaster antontrygubO_o\">antontrygubO_o</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Heltion\" title=\"Legendary Grandmaster Heltion\"><span class=\"legendary-user-first-letter\">H</span>eltion</a></li> <li><a class=\"rated-user user-orange\" href=\"/profile/KumaTachiRen\" title=\"Master KumaTachiRen\">KumaTachiRen</a></li> </ol></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120644\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1882\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 899 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-272374-121269\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"272374\",\n blogEntryId: \"120644\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+524</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121269\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/windva\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/windva\">\n windva\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/22/2023 01:56\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120644#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120644#comments\">\n 188\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121269\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121269, _tta: Codeforces.tta(), topicRevisionId: 321556, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121316\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120691\"> <p>Educational Codeforces Round 155 [Rated for Div. 2]</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a>,\r\n <a href=\"/topic/121316/en5\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p>On <a class=\"contest-time\" contestid=\"1879\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=24&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/24/2023 17:35 (Moscow time)</span></a> <a href=\"/contest/1879\" title=\"Educational Codeforces Round 155 (Rated for Div. 2)\">Educational Codeforces Round 155 (Rated for Div. 2)</a> will start.</p><p>Series of Educational Rounds continue being held as <a href=\"https://harbour.space/\">Harbour.Space University</a> initiative! You can read the details about the cooperation between <a href=\"https://harbour.space/\">Harbour.Space University</a> and Codeforces in the <a href=\"https://mirror.codeforces.com/blog/entry/51208\">blog post</a>.</p><p>This round will be <strong>rated for the participants with rating lower than 2100</strong>. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.</p><p>You will be given <strong>6 or 7 problems</strong> and <strong>2 hours</strong> to solve them.</p><p>The problems were invented and prepared by Adilbek <a class=\"rated-user user-orange\" href=\"/profile/adedalic\" title=\"International Master adedalic\">adedalic</a> Dalabaev, Ivan <a class=\"rated-user user-red\" href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\">BledDest</a> Androsov, Maksim <a class=\"rated-user user-violet\" href=\"/profile/Neon\" title=\"Candidate Master Neon\">Neon</a> Mescheryakov, Roman <a class=\"rated-user user-orange\" href=\"/profile/Roms\" title=\"Master Roms\">Roms</a> Glazov and me. Also, huge thanks to Mike <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> Mirzayanov for great systems Polygon and Codeforces.</p><p>Good luck to all the participants!</p><p>Our friends at Harbour.Space also have a message for you:</p> <center><img alt=\"Harbour.Space\" src=\"/predownloaded/29/a4/29a4884273346021dec6559e9785af37a662cc56.png\" style=\"height: 200.0px;margin: 10.0px;max-width: 100.0%;max-height: 100.0%;\" /></center> <center style=\"margin: 1.0em;\"><b>FULLY FUNDED SCHOLARSHIPS for Masters in Data Science and Computer Science </b></center><p><em>Scholarships for Master's students in <a href=\"https://harbour.space/computer-science\">Computer Science</a> and <a href=\"https://harbour.space/data-science\">Data Science</a> are available in <a href=\"https://harbour.space\">Harbour.Space University</a> Barcelona campus!</em> </p><p><strong>Scholarship Summary:</strong></p> <ul> <li><em>Fully funded scholarship (29.900 โฌ/year) to study a Masterโs degree in Data Science or Computer Science for two years</em></li> <li><em>Successful applicants will become part of the Universityโs โTalent poolโ and will be shown to the sponsoring companies. In case the candidate is picked for the Work&Study Program from our industry partner, the student starts an internship with a commitment to study 3 hours/day and work for 4 hour/day</em></li> </ul><p><em>Please note preselected candidates will be requested to pay a non-refundable application fee of 85โฌ to study at Harbour.Space University.</em></p><p><em><strong>Candidateโs commitment:</strong></em></p><p><em>You will complete 15 modules (each three weeks long) in one year. The daily class workload is 3 hours, plus homework to complete in your own time.</em></p><p><em><strong>Candidateโs requirements:</strong></em> </p> <ul> <li><em>Bachelor's degree in the field of Mathematics, Statistics, Data Science, Computer Science or similar</em></li> <li><em>English proficiency</em></li> <li><em>Advanced knowledge and experience in Python, SQL, Spark/Scala, and bash</em></li> <li><em>Experienced use of Big Data technologies: Spark, HDFS, Kafka, etc.</em></li> <li><em>Hands-on experience with Data Science techniques: feature engineering,</em></li> <li><em>Strong ML knowledge</em></li> <li><em>Strong Software Engineering Background</em></li> <li><em>Problem-solving aptitude</em></li> </ul> <center style=\"margin: 2.5em;\"> <a href=\"https://harbour.space/account/apply-process?utm_source=codeforces&utm_medium=partner&utm_campaign=bcn_b2b\" style=\"text-decoration: none;font-size: 14.0px;background-color: rgb(98,91,183);color: white;font-weight: bold;padding: 0.5em 1.0em;\">Apply here โ</a> </center><p><strong>UPD:</strong> <a href=\"https://codeforces.com/blog/entry/120773\">Editorial is out</a> </p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120691\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1879\" class=\"notice\" style=\"text-decoration: none;\">Educational Codeforces Round 155 (Rated for Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-42750-121316\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"42750\",\n blogEntryId: \"120691\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+245</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121316\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/awoo\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/awoo\">\n awoo\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/23/2023 16:55\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120691#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120691#comments\">\n 189\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121316\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121316, _tta: Codeforces.tta(), topicRevisionId: 321525, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121227\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120602\"> <p>Codeforces Round 898 (Div. 4)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/mesanu\" title=\"Candidate Master mesanu\" class=\"rated-user user-violet\">mesanu</a>,\r\n <a href=\"/topic/121227/en2\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello Codeforces!</p><p><a class=\"rated-user user-violet\" href=\"/profile/flamestorm\" title=\"Candidate Master flamestorm\">flamestorm</a>, <a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and I want to invite you to <a href=\"/contest/1873\" title=\"Codeforces Round 898 (Div. 4)\">Codeforces Round 898 (Div. 4)</a>.</p><p>It starts on <a class=\"contest-time\" contestid=\"1873\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=21&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/21/2023 17:35 (Moscow time)</span></a>.</p><p>The format of the event will be identical to Div. 3 rounds:</p> <ul> <li>5-8 tasks;</li> <li>ICPC rules with a penalty of 10 minutes for an incorrect submission;</li> <li>12-hour phase of open hacks after the end of the round (hacks do not give additional points)</li> <li>after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated</li> <li>by default, only "trusted" participants are shown in the results table (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).</li> </ul><p>We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.</p><p>Only <em>trusted participants of the fourth division</em> will be included in the official standings table. This is a forced measure for combating unsporting behaviour. To qualify as <em>a trusted participant of the fourth division</em>, you must:</p> <ul> <li>take part in at least five rated rounds (and solve at least one problem in each of them),</li> <li>do not have a point of 1400 or higher in the rating.</li> </ul><p><strong>Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), then the round will be rated for you.</strong></p><p>Many thanks to the testers: <a class=\"rated-user user-orange\" href=\"/profile/Gheal\" title=\"Master Gheal\">Gheal</a>, <a class=\"rated-user user-orange\" href=\"/profile/Phantom_Performer\" title=\"Master Phantom_Performer\">Phantom_Performer</a>, <a class=\"rated-user user-orange\" href=\"/profile/KrowSavcik\" title=\"Master KrowSavcik\">KrowSavcik</a>, <a class=\"rated-user user-cyan\" href=\"/profile/haochenkang\" title=\"Specialist haochenkang\">haochenkang</a>, <a class=\"rated-user user-cyan\" href=\"/profile/sandry24\" title=\"Specialist sandry24\">sandry24</a>, <a class=\"rated-user user-red\" href=\"/profile/BucketPotato\" title=\"Grandmaster BucketPotato\">BucketPotato</a>, <a class=\"rated-user user-blue\" href=\"/profile/Vladosiya\" title=\"Expert Vladosiya\">Vladosiya</a>, <a class=\"rated-user user-violet\" href=\"/profile/NintsiChkhaidze\" title=\"Candidate Master NintsiChkhaidze\">NintsiChkhaidze</a>, <a class=\"rated-user user-orange\" href=\"/profile/erekle\" title=\"International Master erekle\">erekle</a>, <a class=\"rated-user user-red\" href=\"/profile/Dominater069\" title=\"Grandmaster Dominater069\">Dominater069</a>, <a class=\"rated-user user-blue\" href=\"/profile/MADE_IN_HEAVEN\" title=\"Expert MADE_IN_HEAVEN\">MADE_IN_HEAVEN</a>, <a class=\"rated-user user-blue\" href=\"/profile/Qualified\" title=\"Expert Qualified\">Qualified</a>.</p><p>We suggest reading all of the problems and hope you will find them interesting!</p><p><strong>Good Luck!</strong></p><p><strong>UPD</strong>: <a href=\"https://codeforces.com/blog/entry/120634\">Editorial is out!</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120602\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1873\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 898 (Div. 4)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-188642-121227\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"188642\",\n blogEntryId: \"120602\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+200</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121227\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/mesanu\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/mesanu\">\n mesanu\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/20/2023 18:05\">2 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120602#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120602#comments\">\n 179\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121227\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121227, _tta: Codeforces.tta(), topicRevisionId: 321112, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"121083\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120458\"> <p>CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/glebustim\" title=\"Grandmaster glebustim\" class=\"rated-user user-red\">glebustim</a>,\r\n <a href=\"/topic/121083/en8\">history</a>,\r\n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><h3>Hello, Codeforces!</h3><p><a class=\"rated-user user-red\" href=\"/profile/SomethingNew\" title=\"International Grandmaster SomethingNew\">SomethingNew</a> and I are glad to invite you to <a href=\"/contest/1870\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a>, which will take place on <a class=\"contest-time\" contestid=\"1870\" href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=18&month=9&year=2023&hour=17&min=35&sec=0&p1=166\"><span class=\"format-time-with-dow\">Sep/18/2023 17:35 (Moscow time)</span></a>. You will have 2 hours 15 minutes to solve 8 problems. The round will be rated for everyone.</p><p>We would like to thank:</p> <ul> <li><a class=\"rated-user user-orange\" href=\"/profile/74TrAkToR\" title=\"International Master 74TrAkToR\">74TrAkToR</a> for coordinating this round.</li> <li><a class=\"rated-user user-legendary\" href=\"/profile/isaf27\" title=\"Legendary Grandmaster isaf27\"><span class=\"legendary-user-first-letter\">i</span>saf27</a>, <a class=\"rated-user user-legendary\" href=\"/profile/ugly2333\" title=\"Legendary Grandmaster ugly2333\"><span class=\"legendary-user-first-letter\">u</span>gly2333</a>, <a class=\"rated-user user-red\" href=\"/profile/DataStructures\" title=\"Grandmaster DataStructures\">DataStructures</a>, <a class=\"rated-user user-red\" href=\"/profile/Little09\" title=\"International Grandmaster Little09\">Little09</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a>, <a class=\"rated-user user-orange\" href=\"/profile/Kieray\" title=\"Master Kieray\">Kieray</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/Vladithur\" title=\"Master Vladithur\">Vladithur</a>, <a class=\"rated-user user-orange\" href=\"/profile/Dart-Xeyter\" title=\"International Master Dart-Xeyter\">Dart-Xeyter</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/meowcneil\" title=\"Master meowcneil\">meowcneil</a>, <a class=\"rated-user user-orange\" href=\"/profile/127.0.0.1\" title=\"Master 127.0.0.1\">127.0.0.1</a>, <a class=\"rated-user user-violet\" href=\"/profile/Nanani\" title=\"Candidate Master Nanani\">Nanani</a>, <a class=\"rated-user user-violet\" href=\"/profile/nnv-nick\" title=\"Candidate Master nnv-nick\">nnv-nick</a>, <a class=\"rated-user user-violet\" href=\"/profile/SomethingDifferent\" title=\"Candidate Master SomethingDifferent\">SomethingDifferent</a>, <a class=\"rated-user user-blue\" href=\"/profile/vl342\" title=\"Expert vl342\">vl342</a>, <a class=\"rated-user user-blue\" href=\"/profile/shiv_codegen\" title=\"Expert shiv_codegen\">shiv_codegen</a>, <a class=\"rated-user user-cyan\" href=\"/profile/M1lkas\" title=\"Specialist M1lkas\">M1lkas</a>, <a class=\"rated-user user-green\" href=\"/profile/allmath\" title=\"Pupil allmath\">allmath</a>, <a class=\"rated-user user-gray\" href=\"/profile/sdyakonov\" title=\"Newbie sdyakonov\">sdyakonov</a> for testing the round and providing useful feedback.</li> <li><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> for Codeforces and Polygon systems.</li> </ul><h4><strong>Score distribution:</strong></h4><p>500 โ 750 โ 1500 โ 1750 โ 2750 โ 3250 โ 3250 โ 4000</p><p>We hope that our problems will be interesting for you!</p><h4><a href=\"https://codeforces.com/blog/entry/120524\">Editorial</a></h4><p><strong>Congratulations to the winners!</strong></p> <ol> <li><a class=\"rated-user user-legendary\" href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/emptyhope\" title=\"Legendary Grandmaster emptyhope\"><span class=\"legendary-user-first-letter\">e</span>mptyhope</a></li> <li><a class=\"rated-user user-red\" href=\"/profile/maspy\" title=\"International Grandmaster maspy\">maspy</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/AoLiGei\" title=\"Legendary Grandmaster AoLiGei\"><span class=\"legendary-user-first-letter\">A</span>oLiGei</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/noimi\" title=\"Legendary Grandmaster noimi\"><span class=\"legendary-user-first-letter\">n</span>oimi</a></li> <li><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></li> </ol><p>And here is the information from our title sponsor:</p><p><img src=\"/predownloaded/ce/9f/ce9f87d5c429f47e7691bef3a8934ebf36af3f15.jpg\" style=\"width: 250.0px;float: right;margin: 0 1.0em 1.0em 1.0em;max-width: 100.0%;max-height: 100.0%;\" /></p><p><em>Hello, Codeforces!</em></p><p><em>We, the <a href=\"https://ton.org/\">TON Foundation</a> team, are pleased to support CodeTON Round 6.</em></p><p><em>The Open Network (TON) is a fully decentralized layer-1 blockchain designed to onboard billions of users to Web3.</em></p><p><em>Since July 2022, <a href=\"/blog/entry/104544\">we have been supporting</a> Codeforces as a title sponsor. This round is another way for us to contribute to the development of the community.</em></p><p><em>The winners of CodeTON Round 6 will receive valuable prizes.</em></p><p><em>The first 1,023 participants will receive prizes in TON cryptocurrency:</em></p> <ul> <li><em>1st place: 1,024 TON</em></li> <li><em>2โ3 places: 512 TON each</em></li> <li><em>4โ7 places: 256 TON each</em></li> <li><em>8โ15 places: 128 TON each</em></li> <li><em>โฆ</em></li> <li><em>512โ1,023 places: 2 TON each</em></li> </ul><p><em>We wish you good luck at CodeTON Round 6 and hope you enjoy the contest!</em></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120458\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1870\" class=\"notice\" style=\"text-decoration: none;\">CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-223600-121083\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"223600\",\n blogEntryId: \"120458\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+394</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-121083\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/glebustim\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/glebustim\">\n glebustim\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/16/2023 14:16\">3 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120458#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120458#comments\">\n 171\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-121083\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 121083, _tta: Codeforces.tta(), topicRevisionId: 320697, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n<div style=\"margin-bottom:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"120865\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/120240\"> <p>Codeforces Round #897 (Div. 2)</p>\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/salyg1n\" title=\"Master salyg1n\" class=\"rated-user user-orange\">salyg1n</a>,\r\n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p>Hello, Codeforces! ๐คฏ</p><p><a class=\"rated-user user-red\" href=\"/profile/green_gold_dog\" title=\"Grandmaster green_gold_dog\">green_gold_dog</a>, <a class=\"rated-user user-orange\" href=\"/profile/ace5\" title=\"International Master ace5\">ace5</a>, <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> and I <a class=\"rated-user user-orange\" href=\"/profile/salyg1n\" title=\"Master salyg1n\">salyg1n</a> are pleased to invite you to participate in <a href=\"https://codeforces.com/contest/1867\">Codeforces Round 897 (Div. 2)</a>, which will take place on <a href=\"https://www.timeanddate.com/worldclock/fixedtime.html?day=11&month=9&year=2023&hour=17&min=35&sec=0&p1=166\">Monday, September 11, 2023 in 17:35</a>.</p><p>This round will be <strong>rated</strong> for participants whose <strong>rating is below 2100</strong>.</p><p>You will be given 6 tasks and 2 hours to solve them. We recommend reading all the tasks. <strong>Interactive tasks may occur in the round</strong>, so we suggest reading this <a href=\"https://codeforces.com/blog/entry/45307\">post</a>.</p><p>We want to thank:</p> <ul> <li><p><a class=\"rated-user user-red\" href=\"/profile/Aleks5d\" title=\"Grandmaster Aleks5d\">Aleks5d</a> for coordinating the round and improving one of the tasks. ๐ค</p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Allvik06\" title=\"International Grandmaster Allvik06\">Allvik06</a>, <a class=\"rated-user user-red\" href=\"/profile/Nutella3000\" title=\"Grandmaster Nutella3000\">Nutella3000</a>, <a class=\"rated-user user-red\" href=\"/profile/arbuzick\" title=\"International Grandmaster arbuzick\">arbuzick</a>, <a class=\"rated-user user-red\" href=\"/profile/alegsandyr\" title=\"Grandmaster alegsandyr\">alegsandyr</a>, <a class=\"rated-user user-red\" href=\"/profile/maomao90\" title=\"Grandmaster maomao90\">maomao90</a>, <a class=\"rated-user user-red\" href=\"/profile/FairyWinx\" title=\"Grandmaster FairyWinx\">FairyWinx</a>, <a class=\"rated-user user-red\" href=\"/profile/zwezdinv\" title=\"Grandmaster zwezdinv\">zwezdinv</a>, <a class=\"rated-user user-orange\" href=\"/profile/valerikk\" title=\"Master valerikk\">valerikk</a>, <a class=\"rated-user user-orange\" href=\"/profile/danya111\" title=\"Master danya111\">danya111</a>, <a class=\"rated-user user-orange\" href=\"/profile/EJIC_B_KEDAX\" title=\"Master EJIC_B_KEDAX\">EJIC_B_KEDAX</a>, <a class=\"rated-user user-orange\" href=\"/profile/dushenkov\" title=\"Master dushenkov\">dushenkov</a>, <a class=\"rated-user user-orange\" href=\"/profile/fishy15\" title=\"Master fishy15\">fishy15</a>, <a class=\"rated-user user-orange\" href=\"/profile/makrav\" title=\"Master makrav\">makrav</a>, <a class=\"rated-user user-orange\" href=\"/profile/pakhomovee\" title=\"International Master pakhomovee\">pakhomovee</a>, <a class=\"rated-user user-orange\" href=\"/profile/aleksandro\" title=\"Master aleksandro\">aleksandro</a>, <a class=\"rated-user user-orange\" href=\"/profile/Yar_sem\" title=\"Master Yar_sem\">Yar_sem</a>, <a class=\"rated-user user-orange\" href=\"/profile/asafiul\" title=\"Master asafiul\">asafiul</a>, <a class=\"rated-user user-violet\" href=\"/profile/Ivan_len\" title=\"Candidate Master Ivan_len\">Ivan_len</a>, <a class=\"rated-user user-violet\" href=\"/profile/ArtAlex\" title=\"Candidate Master ArtAlex\">ArtAlex</a>, <a class=\"rated-user user-violet\" href=\"/profile/Undying\" title=\"Candidate Master Undying\">Undying</a>, <a class=\"rated-user user-violet\" href=\"/profile/JustNik77\" title=\"Candidate Master JustNik77\">JustNik77</a>, <a class=\"rated-user user-violet\" href=\"/profile/Pavarishko\" title=\"Candidate Master Pavarishko\">Pavarishko</a> and <a class=\"rated-user user-violet\" href=\"/profile/xnor\" title=\"Candidate Master xnor\">xnor</a> for testing the round and giving valuable feedback. ๐ <span style=\"color: rgb(255,255,255);\">orz</span></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/ryskmax\" title=\"Expert ryskmax\">ryskmax</a> for being the only blue tester and giving valuable feedback. ๐ณ </p></li> <li><p><a class=\"rated-user user-orange\" href=\"/profile/DimaTomsk\" title=\"Master DimaTomsk\">DimaTomsk</a> and <a class=\"rated-user user-orange\" href=\"/profile/ilyakrasnovv\" title=\"Master ilyakrasnovv\">ilyakrasnovv</a> for viewing some of the tasks and giving valuable feedback. ๐ค <span style=\"color: rgb(255,255,255);\"></span></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/stepanov.aa\" title=\"Grandmaster stepanov.aa\">stepanov.aa</a> for <strong>not</strong> testing the round. ๐ฆฅ <span style=\"color: rgb(255,255,255);\">:(</span></p></li> <li><p>The authors of the task <em>5. Overtaking</em> from IOI 2023 for <a class=\"rated-user user-red\" href=\"/profile/bashkort\" title=\"Grandmaster bashkort\">bashkort</a> taking a <strong>gold medal</strong>. ๐ฅ <span style=\"color: rgb(255,255,255);\">Too dead? Yes, so am I.</span></p></li> <li><p><a class=\"rated-user user-admin\" href=\"/profile/MikeMirzayanov\" title=\"Headquarters, MikeMirzayanov\">MikeMirzayanov</a> and <a class=\"rated-user user-admin\" href=\"/profile/geranazavr555\" title=\"Headquarters, geranazavr555\">geranazavr555</a> for the excellent codeforces and polygon platforms. ๐ฆ <span style=\"color: rgb(255,255,255);\">Thank you!</span></p></li> </ul><p>We hope you'll enjoy our problems! Good luck!</p><p><strong>UPD.</strong> Score distribution: $$$500 - 1000 - 1250 - 2000 - (2000 + 1000) - 4000$$$.</p><p><strong>UPD2.</strong> Congratulations to the winners!</p><p><strong>Div. 2</strong></p> <ol> <li><p><a class=\"rated-user user-violet\" href=\"/profile/candidatecandidatemaster\" title=\"Candidate Master candidatecandidatemaster\">candidatecandidatemaster</a></p></li> <li><p><a class=\"rated-user user-cyan\" href=\"/profile/Coreopsis\" title=\"Specialist Coreopsis\">Coreopsis</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/iFFT\" title=\"Expert iFFT\">iFFT</a></p></li> <li><p><a class=\"rated-user user-blue\" href=\"/profile/Dorothy__\" title=\"Expert Dorothy__\">Dorothy__</a></p></li> <li><p><a class=\"rated-user user-gray\" href=\"/profile/wfoifysaasisufgv\" title=\"Newbie wfoifysaasisufgv\">wfoifysaasisufgv</a></p></li> </ol><p><strong>Div. 1</strong></p> <ol> <li><p><a class=\"rated-user user-red\" href=\"/profile/Golovanov399\" title=\"International Grandmaster Golovanov399\">Golovanov399</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/Geothermal\" title=\"Legendary Grandmaster Geothermal\"><span class=\"legendary-user-first-letter\">G</span>eothermal</a></p></li> <li><p><a class=\"rated-user user-legendary\" href=\"/profile/arvindf232\" title=\"Legendary Grandmaster arvindf232\"><span class=\"legendary-user-first-letter\">a</span>rvindf232</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Rubikun\" title=\"International Grandmaster Rubikun\">Rubikun</a></p></li> <li><p><a class=\"rated-user user-red\" href=\"/profile/Vercingetorix\" title=\"International Grandmaster Vercingetorix\">Vercingetorix</a></p></li> </ol><p><strong>UPD3.</strong> <a href=\"https://codeforces.com/blog/entry/120353\">Editorial.</a></p></div>\r\n\r\n <p class=\"topic-options\">\r\n <a class=\"topic-read-more\" href=\"/blog/entry/120240\">Full text and comments ยป</a>\r\n </p>\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Announcement of <a href=\"/contest/1867\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Round 897 (Div. 2)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-230855-120865\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"230855\",\n blogEntryId: \"120240\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+280</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-120865\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/salyg1n\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/salyg1n\">\n salyg1n\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Sep/09/2023 17:34\">4 weeks ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/120240#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/120240#comments\">\n 218\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".topic-vote-up-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: +1}, function(data) {\r\n Codeforces.showMessage(data);\r\n }, \"json\");\r\n return false;\r\n });\r\n $(\".topic-vote-down-120865\").click(function () {\r\n $.post(\"/data/topic/vote\", {topicId: 120865, _tta: Codeforces.tta(), topicRevisionId: 320121, vote: -1}, function(data) {\r\n Codeforces.showMessage(data);\r\n adjustTopicComplainFrames();\r\n }, \"json\");\r\n return false;\r\n });\r\n });\n </script>\n</div>\r\n</div>\r\n\r\n<div class=\"pagination\">\r\n <ul>\r\n <span class=\"inactive\">←</span>\r\n <li>\r\n <span class=\"page-index active\" pageIndex=\"1\"><a href=\"/page/1\">1</a></span>\r\n </li>\r\n <li>\r\n <span class=\"page-index\" pageIndex=\"2\"><a href=\"/page/2\">2</a></span>\r\n </li>\r\n <li>\r\n <span 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Noldbach problem"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Noldbach problem</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick is interested in prime numbers. Once he read about <span class=\"tex-font-style-underline\">Goldbach problem</span>. It states that every even integer greater than <span class=\"tex-span\">2</span> can be expressed as the sum of two primes. That got Nick's attention and he decided to invent a problem of his own and call it <span class=\"tex-font-style-underline\">Noldbach problem</span>. Since Nick is interested only in prime numbers, Noldbach problem states that at least <span class=\"tex-span\"><i>k</i></span> prime numbers from <span class=\"tex-span\">2</span> to <span class=\"tex-span\"><i>n</i></span> inclusively can be expressed as the sum of three integer numbers: two neighboring prime numbers and <span class=\"tex-span\">1</span>. For example, <span class=\"tex-font-style-tt\">19</span> = <span class=\"tex-font-style-tt\">7</span> + <span class=\"tex-font-style-tt\">11</span> + <span class=\"tex-font-style-tt\">1</span>, or <span class=\"tex-font-style-tt\">13</span> = <span class=\"tex-font-style-tt\">5</span> + <span class=\"tex-font-style-tt\">7</span> + <span class=\"tex-font-style-tt\">1</span>.</p><p>Two prime numbers are called neighboring if there are no other prime numbers between them.</p><p>You are to help Nick, and find out if he is right or wrong.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two integers <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ1000</span>) and <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">0โโคโ<i>k</i>โโคโ1000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-font-style-tt\">YES</span> if at least <span class=\"tex-span\"><i>k</i></span> prime numbers from <span class=\"tex-span\">2</span> to <span class=\"tex-span\"><i>n</i></span> inclusively can be expressed as it was described above. Otherwise output <span class=\"tex-font-style-tt\">NO</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>27 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>45 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample the answer is <span class=\"tex-font-style-tt\">YES</span> since at least two numbers can be expressed as it was described (for example, 13 and 19). In the second sample the answer is <span class=\"tex-font-style-tt\">NO</span> since it is impossible to express 7 prime numbers from 2 to 45 in the desired form.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c0baae575d518f59eca3ebf53bd1d511\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"924de51dea4e325c3899bda42e8b7bd9c6a75d69\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/17\">Codeforces Beta Round 17</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/17/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Mathematics including integration, differential equations, etc\">\r\n math\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Number theory: Euler function, GCD, divisibility, etc\">\r\n number theory\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='c0baae575d518f59eca3ebf53bd1d511'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"77\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='c0baae575d518f59eca3ebf53bd1d511'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"77\"/>\r\n <input name=\"tagName\" type=\"hidden\" 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class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_5e973879db6a6aeca15515be725aa8373440ae18\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Noldbach problem</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick is interested in prime numbers. Once he read about <span class=\"tex-font-style-underline\">Goldbach problem</span>. It states that every even integer greater than <span class=\"tex-span\">2</span> can be expressed as the sum of two primes. That got Nick's attention and he decided to invent a problem of his own and call it <span class=\"tex-font-style-underline\">Noldbach problem</span>. Since Nick is interested only in prime numbers, Noldbach problem states that at least <span class=\"tex-span\"><i>k</i></span> prime numbers from <span class=\"tex-span\">2</span> to <span class=\"tex-span\"><i>n</i></span> inclusively can be expressed as the sum of three integer numbers: two neighboring prime numbers and <span class=\"tex-span\">1</span>. For example, <span class=\"tex-font-style-tt\">19</span> = <span class=\"tex-font-style-tt\">7</span> + <span class=\"tex-font-style-tt\">11</span> + <span class=\"tex-font-style-tt\">1</span>, or <span class=\"tex-font-style-tt\">13</span> = <span class=\"tex-font-style-tt\">5</span> + <span class=\"tex-font-style-tt\">7</span> + <span class=\"tex-font-style-tt\">1</span>.</p><p>Two prime numbers are called neighboring if there are no other prime numbers between them.</p><p>You are to help Nick, and find out if he is right or wrong.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two integers <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ1000</span>) and <span class=\"tex-span\"><i>k</i></span> (<span class=\"tex-span\">0โโคโ<i>k</i>โโคโ1000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-font-style-tt\">YES</span> if at least <span class=\"tex-span\"><i>k</i></span> prime numbers from <span class=\"tex-span\">2</span> to <span class=\"tex-span\"><i>n</i></span> inclusively can be expressed as it was described above. Otherwise output <span class=\"tex-font-style-tt\">NO</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>27 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>45 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample the answer is <span class=\"tex-font-style-tt\">YES</span> since at least two numbers can be expressed as it was described (for example, 13 and 19). In the second sample the answer is <span class=\"tex-font-style-tt\">NO</span> since it is impossible to express 7 prime numbers from 2 to 45 in the desired form.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, 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class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='db02a831347ebee346bb8256eecc937c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a>,\r\n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/blog/entry/447\">Contest discussion</a><br /><b><br />Problem A. Noldbach problem<br /><br /></b>To solve this problem you were to find prime numbers in range <span class=\"tex-span\">[2..<i>N</i>]</span>. The constraints were pretty small, so you could do that in any way - using the Sieve of Eratosthenes or simply looping over all possible divisors of a number.<br />Take every pair of neighboring prime numbers and check if their sum increased by <span class=\"tex-span\">1</span> is a prime number too. Count the number of these pairs, compare it to <span class=\"tex-span\"><i>K</i></span> and output the result.<br /><br /><b>Problem B. Hierarchy</b><br /> <br />Note that if employee, except one, has exactly one supervisor, then our hierarchy will be tree-like for sure.<br />For each employee consider all applications in which he appears as a subordinate. If for more than one employee there are no such applications at all, it's obvious that <span class=\"tex-span\">โ-โ1</span> is the answer. In other case, for each employee find such an application with minimal cost and add these costs to get the answer.<br />Alternatively, you could use Kruskal's algorithm finding a minimum spanning tree for a graph. But you should be careful so that you don't assign the second supervisor to some employee.<br />And yes, the employees' qualifications weren't actually needed to solve this problem :)<br /><br /><b>Problem C. Balance<br /></b><br />Consider the input string <span class=\"tex-span\"><i>A</i></span> of length <span class=\"tex-span\"><i>n</i></span>. Let's perform some operations from the problem statement on this string; suppose we obtained some string <span class=\"tex-span\"><i>B</i></span>. Let <i>compression</i> of string <span class=\"tex-span\"><i>X</i></span> be a string <span class=\"tex-span\"><i>X</i>'</span> obtained from <span class=\"tex-span\"><i>X</i></span> by replacing all consecutive equal letters with one such letter. For example, if <span class=\"tex-span\"><i>S</i>โ=โ"<i>aabcccbbaa</i>"</span>, then its compression <span class=\"tex-span\"><i>S</i>'โ=โ"<i>abcba</i>"</span>.<br />Now, consider compressions of strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> - <span class=\"tex-span\"><i>A</i>'</span> and <span class=\"tex-span\"><i>B</i>'</span>. It can be proven that if <span class=\"tex-span\"><i>B</i></span> can be obtained from some string <span class=\"tex-span\"><i>A</i></span> using some number of operations from the problem statement, then <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, and vice versa - if for any strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> of equal length <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, then string <span class=\"tex-span\"><i>B</i></span> can be obtained from string <span class=\"tex-span\"><i>A</i></span> using some number of operations.<br />Intuitively you can understand it in this manner: suppose we use some letter <span class=\"tex-span\"><i>a</i></span> from position <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>A</i></span> in order to put letter <span class=\"tex-span\"><i>a</i></span> at positions <span class=\"tex-span\"><i>j</i>..<i>k</i></span> of <span class=\"tex-span\"><i>B</i></span> (again, using problem statement operations). Then we can't use letters at positions <span class=\"tex-span\">1..<i>i</i>โ-โ1</span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\"><i>k</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>B</i></span> in any way; also, we can't use letters at positions <span class=\"tex-span\"><i>i</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\">1..<i>j</i>โ-โ1</span> of string <span class=\"tex-span\"><i>B</i></span>.<br /><br />Now we have some basis for our solution, which will use dynamic programming. We'll form string <span class=\"tex-span\"><i>B</i></span> letter by letter, considering the fact that <span class=\"tex-span\"><i>B</i>'</span> should still be a subsequence of <span class=\"tex-span\"><i>A</i>'</span> (that is, we'll search for <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> while forming <span class=\"tex-span\"><i>B</i></span>). For this matter we'll keep some position <span class=\"tex-span\"><i>i</i></span> in string <span class=\"tex-span\"><i>A</i>'</span> denoting where we stopped searching <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> at the moment, and three variables <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span>, denoting the frequences of characters <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> respectively in string <span class=\"tex-span\"><i>B</i></span>. Here are the transitions of our DP:<br />1) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>a</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>a</i>'</sub>,โ<i>kA</i>โ+โ1,โ<i>kB</i>,โ<i>kC</i>)</span>.<br />2) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>b</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>b</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>โ+โ1,โ<i>kC</i>)</span>.<br />3) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>c</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>c</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โ+โ1)</span>.<br />Where <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is equal to minimal <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>j</i>โโฅโ<i>i</i></span> and <span class=\"tex-span\"><i>A</i>'<sub class=\"lower-index\"><i>j</i></sub>โ=โ<i>x</i></span> (that is, the nearest occurrence of character <span class=\"tex-span\"><i>x</i></span> in <span class=\"tex-span\"><i>A</i>'</span>, starting from position <span class=\"tex-span\"><i>i</i></span>). Clearly, if in some case <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is undefined, then the corresponding transition is impossible.<br />Having calculated <span class=\"tex-span\"><i>f</i>(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span>, it's easy to find the answer: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c535315cd62cf85c44079a977c735e791f53a1d9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for all triples <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span> for which the balance condition is fulfilled.<br /><br />Such a solution exceeds time and memory limits. Note that if string <span class=\"tex-span\"><i>B</i></span> is going to be balanced, then <span class=\"tex-span\"><i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โโคโ(<i>n</i>โ+โ2)โ/โ3</span>, so the number of states can be reduced up to 27 times. But it's also possible to decrease memory usage much storing matrix <span class=\"tex-span\"><i>f</i></span> by layers, where each layer is given by some value of <span class=\"tex-span\"><i>kA</i></span> (or <span class=\"tex-span\"><i>kB</i></span> or <span class=\"tex-span\"><i>kC</i></span>). It's possible since the value of <span class=\"tex-span\"><i>kA</i></span> is increased either by <span class=\"tex-span\">0</span> or by <span class=\"tex-span\">1</span> in each transition.<br /><br />The overall complexity is <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span> with a quite small constant.<br /><b><br />Problem D. Notepad</b><br /><br />The answer to the problem is <span class=\"tex-span\"><i>b</i><sup class=\"upper-index\"><i>n</i>โ-โ1</sup>โ*โ(<i>b</i>โ-โ1)</span> mod <span class=\"tex-span\"><i>c</i></span>. The main thing you should be able to do in this problem - count the value ofย <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>C</i></span> for some long numbers <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and a short number <span class=\"tex-span\"><i>C</i></span>. Simple exponentiation by squaring exceeds time limit since to converse of <span class=\"tex-span\"><i>B</i></span> to binary you need about <span class=\"tex-span\"><i>O</i>(|<i>B</i>|<sup class=\"upper-index\">2</sup>)</span> operations, where <span class=\"tex-span\">|<i>B</i>|</span> is the number of digits in decimal representation of number <span class=\"tex-span\"><i>B</i></span>.<br />The first thing to do is to transform <span class=\"tex-span\"><i>A</i></span> to <span class=\"tex-span\"><i>A</i></span> mod <span class=\"tex-span\"><i>C</i></span>. It isn't difficult to understand that this transformation doesn't change the answer.<br />Let's represent <span class=\"tex-span\"><i>C</i></span> as <span class=\"tex-span\"><i>C</i>โ=โ<i>p</i><sub class=\"lower-index\">1</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">1</sub></sup><i>p</i><sub class=\"lower-index\">2</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">2</sub></sup>...<i>p</i><sub class=\"lower-index\"><i>m</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>, where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are different prime numbers.<br />Calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for all <span class=\"tex-span\"><i>i</i></span> in the following way. There are two possible cases:<br />1) <span class=\"tex-span\"><i>A</i></span> is not divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are coprime, and you can use <a href=\"https://en.wikipedia.org/wiki/Euler%27s_theorem\">Euler's theorem</a>: <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i>'</sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> (mod <span class=\"tex-span\"><i>C</i></span>), where <span class=\"tex-span\"><i>B</i>'โ=โ<i>B</i></span> mod <span class=\"tex-span\">ฯ(<i>C</i>)</span> and <span class=\"tex-span\">ฯ(<i>C</i>)</span> is Euler's totient function;<br />2) <span class=\"tex-span\"><i>A</i></span> is divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then if <span class=\"tex-span\"><i>B</i>โโฅโ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ0</span>, and if <span class=\"tex-span\"><i>B</i>โ<โ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then you can calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in any way since B is very small.<br />Since all <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> are pairwise coprime you may use <a href=\"https://en.wikipedia.org/wiki/Chinese_remainder_theorem\">chinese remainder theorem</a> to obtain the answer.<br /><br />You can also use Euler's theorem directly. Note that if for some <span class=\"tex-span\"><i>B</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>โโฅโ29</span> you know that <span class=\"tex-span\">|<i>B</i><sub class=\"lower-index\">1</sub>โ-โ<i>B</i><sub class=\"lower-index\">2</sub>|</span> mod <span class=\"tex-span\">ฯ(<i>C</i>)โ=โ0</span>, then all <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> for them will be the same (<span class=\"tex-span\">29</span> is the maximal possible value of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>). Using that you may reduce <span class=\"tex-span\"><i>B</i></span> so that it becomes relatively small and obtain the answer using exponentiation by squaring.<br /><br />There is another solution used by many contestants. Represent <span class=\"tex-span\"><i>B</i></span> as <span class=\"tex-span\"><i>B</i>โ=โ<i>d</i><sub class=\"lower-index\">0</sub>โ+โ10<i>d</i><sub class=\"lower-index\">1</sub>โ+โ10<sup class=\"upper-index\">2</sup><i>d</i><sub class=\"lower-index\">2</sub>โ+โ...โ+โ10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></span>, where <span class=\"tex-span\">0โโคโ<i>d</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ9</span> (in fact <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> is the <span class=\"tex-span\"><i>i</i></span>-th digit of <span class=\"tex-span\"><i>B</i></span> counting from the last). Since <span class=\"tex-span\"><i>a</i><sup class=\"upper-index\"><i>x</i>โ+โ<i>y</i></sup>โ=โ<i>a</i><sup class=\"upper-index\"><i>x</i></sup>ยท <i>a</i><sup class=\"upper-index\"><i>y</i></sup></span>, you know that <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\">0</sub></sup>ยท <i>A</i><sup class=\"upper-index\">10<i>d</i><sub class=\"lower-index\">1</sub></sup>ยท ...ยท <i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>. The values of <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span> can be obtained by successive exponentiation (that is, <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i>โ-โ1</sub><sup class=\"upper-index\">10</sup></span>); if you have <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span>, it's easy to get <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. The answer is the product above (modulo <span class=\"tex-span\"><i>C</i></span>, of course).<br /><br /><b>Problem E. Palisection</b><br /><b><br /></b>The first thing to do is to find all subpalindromes in the given string. For this you may use a beautiful algorithm described for example <a href=\"http://www.akalin.cx/2007/11/28/finding-the-longest-palindromic-substring-in-linear-time/\">here</a>. In short, this algorithm find the maximal length of a subpalindrome with its center either at position <span class=\"tex-span\"><i>i</i></span> of the string or between positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i>โ+โ1</span> for each possible placement of the center.<br />For example, suppose that the maximal subpalindrome length with center at position <span class=\"tex-span\"><i>i</i></span> is <span class=\"tex-span\">5</span>; it means that there are three subpalindromes with center at <span class=\"tex-span\"><i>i</i></span>, with lengths <span class=\"tex-span\">1</span> (<span class=\"tex-span\"><i>i</i>..<i>i</i></span>), <span class=\"tex-span\">3</span> (<span class=\"tex-span\"><i>i</i>โ-โ1..<i>i</i>โ+โ1</span>) and <span class=\"tex-span\">5</span> (<span class=\"tex-span\"><i>i</i>โ-โ2..<i>i</i>โ+โ2</span>). In general, all starting and finishing positions of subpalindromes with a fixed center lie on some interval of positions, which is pretty easy to find.<br />Let's find for each position <span class=\"tex-span\"><i>i</i></span> the value of <span class=\"tex-span\"><i>start</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes starting at position <span class=\"tex-span\"><i>i</i></span>. All these values can be found in linear time. Let's create an auxiliary array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If after processing a position in the string some new pack of subpalindromes was found and they start at positions <span class=\"tex-span\"><i>i</i>..<i>j</i></span>, then increase the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> by <span class=\"tex-span\">1</span>, and decrease the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> by <span class=\"tex-span\">1</span>. Now <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/044b5bba9f36a6f4c4c60731bc951bd5f5502393.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Proving this fact is left as an exercise to the reader :)<br />In a similar way it's possible to calculate <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes finishing at position <span class=\"tex-span\"><i>i</i></span>.<br />Since it's easy to count the total number of subpalindromes, let's find the number of <b>non</b>-intersecting pairs of subpalindromes and subtract this number from the total number of pairs to obtain the answer. Note that if two subpalindromes don't intersect then one of them lies strictly to the left of the other one in the string. Then, the number of non-intersecting pairs of subpalindromes is equal to: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5d386dc072593340d4780c81993c93d11bb5a7a5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /><br />This can be calculated in linear time if the value of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c06dd8724651d1b78ba36f10ed6d42d2e3eb20a6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is recalculated by addition of <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span> before moving from position <span class=\"tex-span\"><i>i</i></span> to position <span class=\"tex-span\"><i>i</i>โ+โ1</span>.<br />The overall complexity of the algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span>.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/17\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 17</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-184-451\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"184\",\n blogEntryId: \"451\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2317\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #17</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=contest\" class=\"tag notice\" style=\"text-decoration: none;\">contest</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+30</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/tourist\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/tourist\">\n tourist\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/451#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/451#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"461\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6342\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 20:47\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6342\" href=\"?#comment-6342\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6342\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6342\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysis. Thank you<span style=\"font-family: verdana , arial , sans-serif;font-size: 12.0px;line-height: 20.0px;\">.</span></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6342 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6342 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6342\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6357\" href=\"?#comment-6357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But what can you say about my solution?</p><p>In fact, it looks like:</p><p>a %= c;</p><p>p = phi(c);</p><p>ans = (a ^ (b % p)) % c;</p><p>if (b >= p && ((a ^ p) % c) == 0)</p><p>ย ย ans = 0;</p><p>Maybe there is some subtle counter-example?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6360\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6360\" href=\"?#comment-6360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What? Are you talking about submit 63341? It's not equivalent to what you wrote.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6360\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6361\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6361\" href=\"?#comment-6361\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6361\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6361\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">If your solution is as you wrote, then I believe it's wrong, at least for the case a = 2, b = 4, c = 12. Your answer is 1 while the correct answer is 2^4 mod 12 = 4.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6361 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6361 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6361\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6363\" commentParentId=\"6361\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6363\" href=\"?#comment-6363\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6361\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6363\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6363\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, of course, my bad memory :)</p><p>a %= c;<br /><br />p = phi(c);<br /><br />ans = (a ^ (b % p)) % c;<br /><br />if (b >= p)</p><p>ย ย ans *= ((a ^ p) % c);</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6363 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6363 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6363\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6366\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6366\" href=\"?#comment-6366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, this is correct. It's almost the same as the second approach described in the analysis (using Euler's theorem directly).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6366\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"509249\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2019 22:30\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-509249\" href=\"?#comment-509249\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"509249\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-509249\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explaine why does this solution work?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-509249 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-509249 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-509249\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6367\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Tactic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Tactic\" title=\"Specialist Tactic\" class=\"rated-user user-cyan\">Tactic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 00:19\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6367\" href=\"?#comment-6367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"3077\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks so much for this analysis! Really appreciated, and I hope you will repeat it in upcoming contests.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6367\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6375\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/removed1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/removed1\" title=\"Expert removed1\" class=\"rated-user user-blue\">removed1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 14:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6375\" href=\"?#comment-6375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In D, simplest generalization of fast exponentiation works well: A^(10*x+y) = (A^10)^x * A^y</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6375\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6391\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/swcai\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/swcai\" title=\"Specialist swcai\" class=\"rated-user user-cyan\">swcai</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 16:22\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6391\" href=\"?#comment-6391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1594\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">No luck on problem C. I used java and got "exceed memory limitation error" when allocating dp[151][52][52][52]. :|</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6391\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6458\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ktuan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/727/avatar/55a648886d2699a9.jpg'/> </a>\n <div><a href=\"/profile/ktuan\" title=\"Master ktuan\" class=\"rated-user user-orange\">ktuan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 05:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6458\" href=\"?#comment-6458\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6458\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6458\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I use dp[kA+kB+kC][151][kA][kB], it sounds worse than your way. However, kA+kB+kC always increases by one in each step of DP, so you can use dp1[151][kA][kB] and dp2[151][kA][kB] instead. It's easy to fit in memory.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6458 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6458 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6458\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6700\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MaxBuzz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/MaxBuzz\" title=\"Candidate Master MaxBuzz\" class=\"rated-user user-violet\">MaxBuzz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 12:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6700\" href=\"?#comment-6700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"85\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You need to allocate a ragged array, like this:<br /><br />int[][][][] dp = new int[151][52][][];<br />for (int i = 0; i < dp.length; ++i) {<br />ย ย ย for (int j = 0; j < 52; ++j) {<br />ย ย ย ย ย ย ย dp[i][j] = new int[52 - j][];<br />ย ย ย ย ย ย ย for (int k = 0; j + k < 52; ++j) {<br />ย ย ย ย ย ย ย ย ย ย ย dp[i][j][k] = new int[52 - j - k];<br />ย ย ย ย ย ย ย }<br />ย ย ย }<br />}<br /><br />This allocates only the elements actually needed by the solution, so fitting in memory limit. <br /><br />C/C++ users may use "full" allocation - unused pages of memory will not be loaded, and ML will not be overcomed. But use it with care - there are some problems (not this one) using "lazy" dynamic programming where it is possible to load all or just too many pages by some tricky tests, even if the number of used cells is acceptable.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6700\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 09:14\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6463\" href=\"?#comment-6463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">A naive 15-line python code gives "runtime error on case 24" on problem D, but I expected something like TLE. What could be the reason for it? I usually code in C++ and I don't know what can cause a runtime error on python.<div>http://pastie.org/private/qsj8vbefe3flrfyuqi6ffq<br /></div><div><br /></div><div>Thank you all!</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6475\" commentParentId=\"6463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 11:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6475\" href=\"?#comment-6475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Stack overflow</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6501\" commentParentId=\"6475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 20:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6501\" href=\"?#comment-6501\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6501\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6501\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Oh, of course. Thank you! I've changed to an iterative function but it gives TL 28 now.<div><a href=\"http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w\">http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w</a><br /></div><div><br /></div><div>I'll try to code the good solution now.</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6501 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6501 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6501\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6477\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/661/avatar/adeb7562762246b4.jpg'/> </a>\n <div><a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" title=\"Candidate Master DDDDDDDDDDDDDDDDDDDDDDDD\" class=\"rated-user user-violet\">DDDDDDDDDDDDDDDDDDDDDDDD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 12:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6477\" href=\"?#comment-6477\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6477\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"661\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6477\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Theย tutorialย is nice.<br />Will you post the tutorialsย for coming contests as well?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6477 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6477 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6477\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8153\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Inf_Zero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Inf_Zero\" title=\"Expert Inf_Zero\" class=\"rated-user user-blue\">Inf_Zero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 16:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8153\" href=\"?#comment-8153\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8153\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4806\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8153\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why can't i view the problem statement in english................................</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8153 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8153 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8153\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10592\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cauchyk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6307/avatar/1be12bd76cca6bd4.jpg'/> </a>\n <div><a href=\"/profile/cauchyk\" title=\"Expert cauchyk\" class=\"rated-user user-blue\">cauchyk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2010 11:13\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10592\" href=\"?#comment-10592\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10592\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"6307\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10592\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysia...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10592 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10592 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10592\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"606285\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/17/2020 14:48\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-606285\" href=\"?#comment-606285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"606285\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"606285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-606285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Blog not visible <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>Unable to parse markup [type=CF_HTML]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-606285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-606285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-606285\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-461\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview461 = true;\r\nvar lastPreviewContent461 = 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":75,"cells":{"problem_id":{"kind":"string","value":"17B"},"contest":{"kind":"string","value":"17"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Hierarchy"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Hierarchy</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick's company employed <span class=\"tex-span\"><i>n</i></span> people. Now Nick needs to build a tree hierarchy of ยซsupervisor-surbodinateยป relations in the company (this is to say that each employee, except one, has exactly one supervisor). There are <span class=\"tex-span\"><i>m</i></span> applications written in the following form: <span class=\"tex-font-style-underline\">ยซemployee <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is ready to become a supervisor of employee <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> at extra cost <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>ยป</span>. The qualification <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>j</i></sub></span> of each employee is known, and for each application the following is true: <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></sub>โ>โ<i>q</i><sub class=\"lower-index\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></sub></span>. </p><p>Would you help Nick calculate the minimum cost of such a hierarchy, or find out that it is impossible to build it.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ1000</span>) โ amount of employees in the company. The following line contains <span class=\"tex-span\"><i>n</i></span> space-separated numbers <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>j</i></sub></span> (<span class=\"tex-span\">0โโคโ<i>q</i><sub class=\"lower-index\"><i>j</i></sub>โโคโ10<sup class=\"upper-index\">6</sup></span>)โ the employees' qualifications. The following line contains number <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">0โโคโ<i>m</i>โโคโ10000</span>) โ amount of received applications. The following <span class=\"tex-span\"><i>m</i></span> lines contain the applications themselves, each of them in the form of three space-separated numbers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ<i>n</i></span>, <span class=\"tex-span\">0โโคโ<i>c</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">6</sup></span>). Different applications can be similar, i.e. they can come from one and the same employee who offered to become a supervisor of the same person but at a different cost. For each application <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></sub>โ>โ<i>q</i><sub class=\"lower-index\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></sub></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only line โ the minimum cost of building such a hierarchy, or <span class=\"tex-font-style-tt\">-1</span> if it is impossible to build it.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>7 2 3 1<br/>4<br/>1 2 5<br/>2 4 1<br/>3 4 1<br/>1 3 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>11<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 2 3<br/>2<br/>3 1 2<br/>3 1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample one of the possible ways for building a hierarchy is to take applications with indexes 1, 2 and 4, which give 11 as the minimum total cost. In the second sample it is impossible to build the required hierarchy, so the answer is <span class=\"tex-font-style-tt\">-1</span>.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"307af9617cc4d9d7edd61b78b72cd485\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"924de51dea4e325c3899bda42e8b7bd9c6a75d69\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dfs and similar\">\r\n dfs and similar\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Disjoint set union\">\r\n dsu\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Shortest paths on weighted and unweighted graphs\">\r\n shortest 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(!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_47823a8281437d566ad9c02729debfb95ebd51c4\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Hierarchy</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick's company employed <span class=\"tex-span\"><i>n</i></span> people. Now Nick needs to build a tree hierarchy of ยซsupervisor-surbodinateยป relations in the company (this is to say that each employee, except one, has exactly one supervisor). There are <span class=\"tex-span\"><i>m</i></span> applications written in the following form: <span class=\"tex-font-style-underline\">ยซemployee <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> is ready to become a supervisor of employee <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> at extra cost <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span>ยป</span>. The qualification <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>j</i></sub></span> of each employee is known, and for each application the following is true: <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></sub>โ>โ<i>q</i><sub class=\"lower-index\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></sub></span>. </p><p>Would you help Nick calculate the minimum cost of such a hierarchy, or find out that it is impossible to build it.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ1000</span>) โ amount of employees in the company. The following line contains <span class=\"tex-span\"><i>n</i></span> space-separated numbers <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>j</i></sub></span> (<span class=\"tex-span\">0โโคโ<i>q</i><sub class=\"lower-index\"><i>j</i></sub>โโคโ10<sup class=\"upper-index\">6</sup></span>)โ the employees' qualifications. The following line contains number <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">0โโคโ<i>m</i>โโคโ10000</span>) โ amount of received applications. The following <span class=\"tex-span\"><i>m</i></span> lines contain the applications themselves, each of them in the form of three space-separated numbers: <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ<i>n</i></span>, <span class=\"tex-span\">0โโคโ<i>c</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">6</sup></span>). Different applications can be similar, i.e. they can come from one and the same employee who offered to become a supervisor of the same person but at a different cost. For each application <span class=\"tex-span\"><i>q</i><sub class=\"lower-index\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></sub>โ>โ<i>q</i><sub class=\"lower-index\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></sub></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only line โ the minimum cost of building such a hierarchy, or <span class=\"tex-font-style-tt\">-1</span> if it is impossible to build it.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />7 2 3 1<br />4<br />1 2 5<br />2 4 1<br />3 4 1<br />1 3 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>11<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 2 3<br />2<br />3 1 2<br />3 1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample one of the possible ways for building a hierarchy is to take applications with indexes 1, 2 and 4, which give 11 as the minimum total cost. 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='db02a831347ebee346bb8256eecc937c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a>,\r\n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/blog/entry/447\">Contest discussion</a><br /><b><br />Problem A. Noldbach problem<br /><br /></b>To solve this problem you were to find prime numbers in range <span class=\"tex-span\">[2..<i>N</i>]</span>. The constraints were pretty small, so you could do that in any way - using the Sieve of Eratosthenes or simply looping over all possible divisors of a number.<br />Take every pair of neighboring prime numbers and check if their sum increased by <span class=\"tex-span\">1</span> is a prime number too. Count the number of these pairs, compare it to <span class=\"tex-span\"><i>K</i></span> and output the result.<br /><br /><b>Problem B. Hierarchy</b><br /> <br />Note that if employee, except one, has exactly one supervisor, then our hierarchy will be tree-like for sure.<br />For each employee consider all applications in which he appears as a subordinate. If for more than one employee there are no such applications at all, it's obvious that <span class=\"tex-span\">โ-โ1</span> is the answer. In other case, for each employee find such an application with minimal cost and add these costs to get the answer.<br />Alternatively, you could use Kruskal's algorithm finding a minimum spanning tree for a graph. But you should be careful so that you don't assign the second supervisor to some employee.<br />And yes, the employees' qualifications weren't actually needed to solve this problem :)<br /><br /><b>Problem C. Balance<br /></b><br />Consider the input string <span class=\"tex-span\"><i>A</i></span> of length <span class=\"tex-span\"><i>n</i></span>. Let's perform some operations from the problem statement on this string; suppose we obtained some string <span class=\"tex-span\"><i>B</i></span>. Let <i>compression</i> of string <span class=\"tex-span\"><i>X</i></span> be a string <span class=\"tex-span\"><i>X</i>'</span> obtained from <span class=\"tex-span\"><i>X</i></span> by replacing all consecutive equal letters with one such letter. For example, if <span class=\"tex-span\"><i>S</i>โ=โ"<i>aabcccbbaa</i>"</span>, then its compression <span class=\"tex-span\"><i>S</i>'โ=โ"<i>abcba</i>"</span>.<br />Now, consider compressions of strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> - <span class=\"tex-span\"><i>A</i>'</span> and <span class=\"tex-span\"><i>B</i>'</span>. It can be proven that if <span class=\"tex-span\"><i>B</i></span> can be obtained from some string <span class=\"tex-span\"><i>A</i></span> using some number of operations from the problem statement, then <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, and vice versa - if for any strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> of equal length <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, then string <span class=\"tex-span\"><i>B</i></span> can be obtained from string <span class=\"tex-span\"><i>A</i></span> using some number of operations.<br />Intuitively you can understand it in this manner: suppose we use some letter <span class=\"tex-span\"><i>a</i></span> from position <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>A</i></span> in order to put letter <span class=\"tex-span\"><i>a</i></span> at positions <span class=\"tex-span\"><i>j</i>..<i>k</i></span> of <span class=\"tex-span\"><i>B</i></span> (again, using problem statement operations). Then we can't use letters at positions <span class=\"tex-span\">1..<i>i</i>โ-โ1</span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\"><i>k</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>B</i></span> in any way; also, we can't use letters at positions <span class=\"tex-span\"><i>i</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\">1..<i>j</i>โ-โ1</span> of string <span class=\"tex-span\"><i>B</i></span>.<br /><br />Now we have some basis for our solution, which will use dynamic programming. We'll form string <span class=\"tex-span\"><i>B</i></span> letter by letter, considering the fact that <span class=\"tex-span\"><i>B</i>'</span> should still be a subsequence of <span class=\"tex-span\"><i>A</i>'</span> (that is, we'll search for <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> while forming <span class=\"tex-span\"><i>B</i></span>). For this matter we'll keep some position <span class=\"tex-span\"><i>i</i></span> in string <span class=\"tex-span\"><i>A</i>'</span> denoting where we stopped searching <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> at the moment, and three variables <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span>, denoting the frequences of characters <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> respectively in string <span class=\"tex-span\"><i>B</i></span>. Here are the transitions of our DP:<br />1) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>a</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>a</i>'</sub>,โ<i>kA</i>โ+โ1,โ<i>kB</i>,โ<i>kC</i>)</span>.<br />2) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>b</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>b</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>โ+โ1,โ<i>kC</i>)</span>.<br />3) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>c</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>c</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โ+โ1)</span>.<br />Where <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is equal to minimal <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>j</i>โโฅโ<i>i</i></span> and <span class=\"tex-span\"><i>A</i>'<sub class=\"lower-index\"><i>j</i></sub>โ=โ<i>x</i></span> (that is, the nearest occurrence of character <span class=\"tex-span\"><i>x</i></span> in <span class=\"tex-span\"><i>A</i>'</span>, starting from position <span class=\"tex-span\"><i>i</i></span>). Clearly, if in some case <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is undefined, then the corresponding transition is impossible.<br />Having calculated <span class=\"tex-span\"><i>f</i>(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span>, it's easy to find the answer: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c535315cd62cf85c44079a977c735e791f53a1d9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for all triples <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span> for which the balance condition is fulfilled.<br /><br />Such a solution exceeds time and memory limits. Note that if string <span class=\"tex-span\"><i>B</i></span> is going to be balanced, then <span class=\"tex-span\"><i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โโคโ(<i>n</i>โ+โ2)โ/โ3</span>, so the number of states can be reduced up to 27 times. But it's also possible to decrease memory usage much storing matrix <span class=\"tex-span\"><i>f</i></span> by layers, where each layer is given by some value of <span class=\"tex-span\"><i>kA</i></span> (or <span class=\"tex-span\"><i>kB</i></span> or <span class=\"tex-span\"><i>kC</i></span>). It's possible since the value of <span class=\"tex-span\"><i>kA</i></span> is increased either by <span class=\"tex-span\">0</span> or by <span class=\"tex-span\">1</span> in each transition.<br /><br />The overall complexity is <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span> with a quite small constant.<br /><b><br />Problem D. Notepad</b><br /><br />The answer to the problem is <span class=\"tex-span\"><i>b</i><sup class=\"upper-index\"><i>n</i>โ-โ1</sup>โ*โ(<i>b</i>โ-โ1)</span> mod <span class=\"tex-span\"><i>c</i></span>. The main thing you should be able to do in this problem - count the value ofย <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>C</i></span> for some long numbers <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and a short number <span class=\"tex-span\"><i>C</i></span>. Simple exponentiation by squaring exceeds time limit since to converse of <span class=\"tex-span\"><i>B</i></span> to binary you need about <span class=\"tex-span\"><i>O</i>(|<i>B</i>|<sup class=\"upper-index\">2</sup>)</span> operations, where <span class=\"tex-span\">|<i>B</i>|</span> is the number of digits in decimal representation of number <span class=\"tex-span\"><i>B</i></span>.<br />The first thing to do is to transform <span class=\"tex-span\"><i>A</i></span> to <span class=\"tex-span\"><i>A</i></span> mod <span class=\"tex-span\"><i>C</i></span>. It isn't difficult to understand that this transformation doesn't change the answer.<br />Let's represent <span class=\"tex-span\"><i>C</i></span> as <span class=\"tex-span\"><i>C</i>โ=โ<i>p</i><sub class=\"lower-index\">1</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">1</sub></sup><i>p</i><sub class=\"lower-index\">2</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">2</sub></sup>...<i>p</i><sub class=\"lower-index\"><i>m</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>, where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are different prime numbers.<br />Calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for all <span class=\"tex-span\"><i>i</i></span> in the following way. There are two possible cases:<br />1) <span class=\"tex-span\"><i>A</i></span> is not divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are coprime, and you can use <a href=\"https://en.wikipedia.org/wiki/Euler%27s_theorem\">Euler's theorem</a>: <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i>'</sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> (mod <span class=\"tex-span\"><i>C</i></span>), where <span class=\"tex-span\"><i>B</i>'โ=โ<i>B</i></span> mod <span class=\"tex-span\">ฯ(<i>C</i>)</span> and <span class=\"tex-span\">ฯ(<i>C</i>)</span> is Euler's totient function;<br />2) <span class=\"tex-span\"><i>A</i></span> is divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then if <span class=\"tex-span\"><i>B</i>โโฅโ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ0</span>, and if <span class=\"tex-span\"><i>B</i>โ<โ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then you can calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in any way since B is very small.<br />Since all <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> are pairwise coprime you may use <a href=\"https://en.wikipedia.org/wiki/Chinese_remainder_theorem\">chinese remainder theorem</a> to obtain the answer.<br /><br />You can also use Euler's theorem directly. Note that if for some <span class=\"tex-span\"><i>B</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>โโฅโ29</span> you know that <span class=\"tex-span\">|<i>B</i><sub class=\"lower-index\">1</sub>โ-โ<i>B</i><sub class=\"lower-index\">2</sub>|</span> mod <span class=\"tex-span\">ฯ(<i>C</i>)โ=โ0</span>, then all <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> for them will be the same (<span class=\"tex-span\">29</span> is the maximal possible value of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>). Using that you may reduce <span class=\"tex-span\"><i>B</i></span> so that it becomes relatively small and obtain the answer using exponentiation by squaring.<br /><br />There is another solution used by many contestants. Represent <span class=\"tex-span\"><i>B</i></span> as <span class=\"tex-span\"><i>B</i>โ=โ<i>d</i><sub class=\"lower-index\">0</sub>โ+โ10<i>d</i><sub class=\"lower-index\">1</sub>โ+โ10<sup class=\"upper-index\">2</sup><i>d</i><sub class=\"lower-index\">2</sub>โ+โ...โ+โ10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></span>, where <span class=\"tex-span\">0โโคโ<i>d</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ9</span> (in fact <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> is the <span class=\"tex-span\"><i>i</i></span>-th digit of <span class=\"tex-span\"><i>B</i></span> counting from the last). Since <span class=\"tex-span\"><i>a</i><sup class=\"upper-index\"><i>x</i>โ+โ<i>y</i></sup>โ=โ<i>a</i><sup class=\"upper-index\"><i>x</i></sup>ยท <i>a</i><sup class=\"upper-index\"><i>y</i></sup></span>, you know that <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\">0</sub></sup>ยท <i>A</i><sup class=\"upper-index\">10<i>d</i><sub class=\"lower-index\">1</sub></sup>ยท ...ยท <i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>. The values of <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span> can be obtained by successive exponentiation (that is, <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i>โ-โ1</sub><sup class=\"upper-index\">10</sup></span>); if you have <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span>, it's easy to get <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. The answer is the product above (modulo <span class=\"tex-span\"><i>C</i></span>, of course).<br /><br /><b>Problem E. Palisection</b><br /><b><br /></b>The first thing to do is to find all subpalindromes in the given string. For this you may use a beautiful algorithm described for example <a href=\"http://www.akalin.cx/2007/11/28/finding-the-longest-palindromic-substring-in-linear-time/\">here</a>. In short, this algorithm find the maximal length of a subpalindrome with its center either at position <span class=\"tex-span\"><i>i</i></span> of the string or between positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i>โ+โ1</span> for each possible placement of the center.<br />For example, suppose that the maximal subpalindrome length with center at position <span class=\"tex-span\"><i>i</i></span> is <span class=\"tex-span\">5</span>; it means that there are three subpalindromes with center at <span class=\"tex-span\"><i>i</i></span>, with lengths <span class=\"tex-span\">1</span> (<span class=\"tex-span\"><i>i</i>..<i>i</i></span>), <span class=\"tex-span\">3</span> (<span class=\"tex-span\"><i>i</i>โ-โ1..<i>i</i>โ+โ1</span>) and <span class=\"tex-span\">5</span> (<span class=\"tex-span\"><i>i</i>โ-โ2..<i>i</i>โ+โ2</span>). In general, all starting and finishing positions of subpalindromes with a fixed center lie on some interval of positions, which is pretty easy to find.<br />Let's find for each position <span class=\"tex-span\"><i>i</i></span> the value of <span class=\"tex-span\"><i>start</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes starting at position <span class=\"tex-span\"><i>i</i></span>. All these values can be found in linear time. Let's create an auxiliary array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If after processing a position in the string some new pack of subpalindromes was found and they start at positions <span class=\"tex-span\"><i>i</i>..<i>j</i></span>, then increase the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> by <span class=\"tex-span\">1</span>, and decrease the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> by <span class=\"tex-span\">1</span>. Now <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/044b5bba9f36a6f4c4c60731bc951bd5f5502393.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Proving this fact is left as an exercise to the reader :)<br />In a similar way it's possible to calculate <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes finishing at position <span class=\"tex-span\"><i>i</i></span>.<br />Since it's easy to count the total number of subpalindromes, let's find the number of <b>non</b>-intersecting pairs of subpalindromes and subtract this number from the total number of pairs to obtain the answer. Note that if two subpalindromes don't intersect then one of them lies strictly to the left of the other one in the string. Then, the number of non-intersecting pairs of subpalindromes is equal to: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5d386dc072593340d4780c81993c93d11bb5a7a5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /><br />This can be calculated in linear time if the value of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c06dd8724651d1b78ba36f10ed6d42d2e3eb20a6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is recalculated by addition of <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span> before moving from position <span class=\"tex-span\"><i>i</i></span> to position <span class=\"tex-span\"><i>i</i>โ+โ1</span>.<br />The overall complexity of the algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span>.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/17\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 17</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-184-451\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"184\",\n blogEntryId: \"451\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2317\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #17</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=contest\" class=\"tag notice\" style=\"text-decoration: none;\">contest</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+30</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/tourist\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/tourist\">\n tourist\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/451#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/451#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"461\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6342\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 20:47\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6342\" href=\"?#comment-6342\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6342\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6342\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysis. Thank you<span style=\"font-family: verdana , arial , sans-serif;font-size: 12.0px;line-height: 20.0px;\">.</span></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6342 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6342 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6342\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6357\" href=\"?#comment-6357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But what can you say about my solution?</p><p>In fact, it looks like:</p><p>a %= c;</p><p>p = phi(c);</p><p>ans = (a ^ (b % p)) % c;</p><p>if (b >= p && ((a ^ p) % c) == 0)</p><p>ย ย ans = 0;</p><p>Maybe there is some subtle counter-example?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6360\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6360\" href=\"?#comment-6360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What? Are you talking about submit 63341? It's not equivalent to what you wrote.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6360\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6361\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6361\" href=\"?#comment-6361\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6361\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6361\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">If your solution is as you wrote, then I believe it's wrong, at least for the case a = 2, b = 4, c = 12. Your answer is 1 while the correct answer is 2^4 mod 12 = 4.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6361 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6361 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6361\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6363\" commentParentId=\"6361\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6363\" href=\"?#comment-6363\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6361\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6363\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6363\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, of course, my bad memory :)</p><p>a %= c;<br /><br />p = phi(c);<br /><br />ans = (a ^ (b % p)) % c;<br /><br />if (b >= p)</p><p>ย ย ans *= ((a ^ p) % c);</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6363 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6363 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6363\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6366\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6366\" href=\"?#comment-6366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, this is correct. It's almost the same as the second approach described in the analysis (using Euler's theorem directly).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6366\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"509249\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2019 22:30\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-509249\" href=\"?#comment-509249\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"509249\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-509249\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explaine why does this solution work?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-509249 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-509249 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-509249\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6367\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Tactic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Tactic\" title=\"Specialist Tactic\" class=\"rated-user user-cyan\">Tactic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 00:19\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6367\" href=\"?#comment-6367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"3077\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks so much for this analysis! Really appreciated, and I hope you will repeat it in upcoming contests.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6367\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6375\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/removed1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/removed1\" title=\"Expert removed1\" class=\"rated-user user-blue\">removed1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 14:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6375\" href=\"?#comment-6375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In D, simplest generalization of fast exponentiation works well: A^(10*x+y) = (A^10)^x * A^y</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6375\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6391\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/swcai\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/swcai\" title=\"Specialist swcai\" class=\"rated-user user-cyan\">swcai</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 16:22\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6391\" href=\"?#comment-6391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1594\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">No luck on problem C. I used java and got "exceed memory limitation error" when allocating dp[151][52][52][52]. :|</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6391\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6458\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ktuan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/727/avatar/55a648886d2699a9.jpg'/> </a>\n <div><a href=\"/profile/ktuan\" title=\"Master ktuan\" class=\"rated-user user-orange\">ktuan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 05:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6458\" href=\"?#comment-6458\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6458\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6458\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I use dp[kA+kB+kC][151][kA][kB], it sounds worse than your way. However, kA+kB+kC always increases by one in each step of DP, so you can use dp1[151][kA][kB] and dp2[151][kA][kB] instead. It's easy to fit in memory.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6458 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6458 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6458\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6700\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MaxBuzz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/MaxBuzz\" title=\"Candidate Master MaxBuzz\" class=\"rated-user user-violet\">MaxBuzz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 12:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6700\" href=\"?#comment-6700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"85\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You need to allocate a ragged array, like this:<br /><br />int[][][][] dp = new int[151][52][][];<br />for (int i = 0; i < dp.length; ++i) {<br />ย ย ย for (int j = 0; j < 52; ++j) {<br />ย ย ย ย ย ย ย dp[i][j] = new int[52 - j][];<br />ย ย ย ย ย ย ย for (int k = 0; j + k < 52; ++j) {<br />ย ย ย ย ย ย ย ย ย ย ย dp[i][j][k] = new int[52 - j - k];<br />ย ย ย ย ย ย ย }<br />ย ย ย }<br />}<br /><br />This allocates only the elements actually needed by the solution, so fitting in memory limit. <br /><br />C/C++ users may use "full" allocation - unused pages of memory will not be loaded, and ML will not be overcomed. But use it with care - there are some problems (not this one) using "lazy" dynamic programming where it is possible to load all or just too many pages by some tricky tests, even if the number of used cells is acceptable.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6700\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 09:14\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6463\" href=\"?#comment-6463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">A naive 15-line python code gives "runtime error on case 24" on problem D, but I expected something like TLE. What could be the reason for it? I usually code in C++ and I don't know what can cause a runtime error on python.<div>http://pastie.org/private/qsj8vbefe3flrfyuqi6ffq<br /></div><div><br /></div><div>Thank you all!</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6475\" commentParentId=\"6463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 11:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6475\" href=\"?#comment-6475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Stack overflow</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6501\" commentParentId=\"6475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 20:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6501\" href=\"?#comment-6501\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6501\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6501\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Oh, of course. Thank you! I've changed to an iterative function but it gives TL 28 now.<div><a href=\"http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w\">http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w</a><br /></div><div><br /></div><div>I'll try to code the good solution now.</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6501 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6501 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6501\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6477\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/661/avatar/adeb7562762246b4.jpg'/> </a>\n <div><a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" title=\"Candidate Master DDDDDDDDDDDDDDDDDDDDDDDD\" class=\"rated-user user-violet\">DDDDDDDDDDDDDDDDDDDDDDDD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 12:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6477\" href=\"?#comment-6477\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6477\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"661\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6477\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Theย tutorialย is nice.<br />Will you post the tutorialsย for coming contests as well?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6477 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6477 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6477\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8153\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Inf_Zero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Inf_Zero\" title=\"Expert Inf_Zero\" class=\"rated-user user-blue\">Inf_Zero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 16:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8153\" href=\"?#comment-8153\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8153\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4806\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8153\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why can't i view the problem statement in english................................</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8153 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8153 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8153\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10592\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cauchyk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6307/avatar/1be12bd76cca6bd4.jpg'/> </a>\n <div><a href=\"/profile/cauchyk\" title=\"Expert cauchyk\" class=\"rated-user user-blue\">cauchyk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2010 11:13\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10592\" href=\"?#comment-10592\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10592\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"6307\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10592\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysia...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10592 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10592 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10592\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"606285\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/17/2020 14:48\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-606285\" href=\"?#comment-606285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"606285\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"606285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-606285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Blog not visible <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>Unable to parse markup [type=CF_HTML]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-606285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-606285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-606285\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-461\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview461 = true;\r\nvar lastPreviewContent461 = 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":76,"cells":{"problem_id":{"kind":"string","value":"17C"},"contest":{"kind":"string","value":"17"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Balance"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Balance</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick likes strings very much, he likes to rotate them, sort them, rearrange characters within a string... Once he wrote a random string of characters <span class=\"tex-font-style-tt\">a</span>, <span class=\"tex-font-style-tt\">b</span>, <span class=\"tex-font-style-tt\">c</span> on a piece of paper and began to perform the following operations: </p><ul> <li> to take two adjacent characters and replace the second character with the first one, </li><li> to take two adjacent characters and replace the first character with the second one </li></ul><p>To understand these actions better, let's take a look at a string ยซ<span class=\"tex-font-style-tt\">abc</span>ยป. All of the following strings can be obtained by performing one of the described operations on ยซ<span class=\"tex-font-style-tt\">abc</span>ยป: ยซ<span class=\"tex-font-style-tt\">bbc</span>ยป, ยซ<span class=\"tex-font-style-tt\">abb</span>ยป, ยซ<span class=\"tex-font-style-tt\">acc</span>ยป. Let's denote the <span class=\"tex-font-style-underline\">frequency of a character</span> for each of the characters <span class=\"tex-font-style-tt\">a</span>, <span class=\"tex-font-style-tt\">b</span> and <span class=\"tex-font-style-tt\">c</span> as the number of occurrences of this character in the string. For example, for string ยซ<span class=\"tex-font-style-tt\">abc</span>ยป: |<span class=\"tex-span\"><i>a</i></span>| = 1, |<span class=\"tex-span\"><i>b</i></span>| = 1, |<span class=\"tex-span\"><i>c</i></span>| = 1, and for string ยซ<span class=\"tex-font-style-tt\">bbc</span>ยป: |<span class=\"tex-span\"><i>a</i></span>| = 0, |<span class=\"tex-span\"><i>b</i></span>| = 2, |<span class=\"tex-span\"><i>c</i></span>| = 1. </p><p>While performing the described operations, Nick sometimes got <span class=\"tex-font-style-underline\">balanced strings</span>. Let's say that a string is balanced, if the frequencies of each character differ by at most 1. That is <span class=\"tex-span\">โ-โ1โโคโ|<i>a</i>|โ-โ|<i>b</i>|โโคโ1</span>, <span class=\"tex-span\">โ-โ1โโคโ|<i>a</i>|โ-โ|<i>c</i>|โโคโ1</span> ะธ <span class=\"tex-span\">โ-โ1โโคโ|<i>b</i>|โ-โ|<i>c</i>|โโคโ1</span>. </p><p>Would you help Nick find the number of different balanced strings that can be obtained by performing the operations described above, perhaps multiple times, on the given string <span class=\"tex-span\"><i>s</i></span>. This number should be calculated modulo <span class=\"tex-span\">51123987</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ150</span>) โ the length of the given string <span class=\"tex-span\"><i>s</i></span>. Next line contains the given string <span class=\"tex-span\"><i>s</i></span>. The initial string can be balanced as well, in this case it should be counted too. The given string <span class=\"tex-span\"><i>s</i></span> consists only of characters <span class=\"tex-font-style-tt\">a</span>, <span class=\"tex-font-style-tt\">b</span> and <span class=\"tex-font-style-tt\">c</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only number โ the number of different balanced strings that can be obtained by performing the described operations, perhaps multiple times, on the given string <span class=\"tex-span\"><i>s</i></span>, modulo <span class=\"tex-span\">51123987</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>abca<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>abbc<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>ab<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample it is possible to get <span class=\"tex-span\">51</span> different strings through the described operations, but only <span class=\"tex-span\">7</span> of them are balanced: ยซ<span class=\"tex-font-style-tt\">abca</span>ยป, ยซ<span class=\"tex-font-style-tt\">bbca</span>ยป, ยซ<span class=\"tex-font-style-tt\">bcca</span>ยป, ยซ<span class=\"tex-font-style-tt\">bcaa</span>ยป, ยซ<span class=\"tex-font-style-tt\">abcc</span>ยป, ยซ<span class=\"tex-font-style-tt\">abbc</span>ยป, ยซ<span class=\"tex-font-style-tt\">aabc</span>ยป. In the second sample: ยซ<span class=\"tex-font-style-tt\">abbc</span>ยป, ยซ<span class=\"tex-font-style-tt\">aabc</span>ยป, ยซ<span class=\"tex-font-style-tt\">abcc</span>ยป. In the third sample there is only one balanced string โ ยซ<span class=\"tex-font-style-tt\">ab</span>ยป itself.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"1c29e8c98952a4365227c5e7f79027ee\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"924de51dea4e325c3899bda42e8b7bd9c6a75d69\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/17\">Codeforces Beta Round 17</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2500\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='1c29e8c98952a4365227c5e7f79027ee'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"79\"/>\r\n <input name=\"tagName\" type=\"hidden\" 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result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_0453e85930319754c43cbdcfdd761eee3d86dd1a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Balance</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>3 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick likes strings very much, he likes to rotate them, sort them, rearrange characters within a string... Once he wrote a random string of characters <span class=\"tex-font-style-tt\">a</span>, <span class=\"tex-font-style-tt\">b</span>, <span class=\"tex-font-style-tt\">c</span> on a piece of paper and began to perform the following operations: </p><ul> <li> to take two adjacent characters and replace the second character with the first one, </li><li> to take two adjacent characters and replace the first character with the second one </li></ul><p>To understand these actions better, let's take a look at a string ยซ<span class=\"tex-font-style-tt\">abc</span>ยป. All of the following strings can be obtained by performing one of the described operations on ยซ<span class=\"tex-font-style-tt\">abc</span>ยป: ยซ<span class=\"tex-font-style-tt\">bbc</span>ยป, ยซ<span class=\"tex-font-style-tt\">abb</span>ยป, ยซ<span class=\"tex-font-style-tt\">acc</span>ยป. Let's denote the <span class=\"tex-font-style-underline\">frequency of a character</span> for each of the characters <span class=\"tex-font-style-tt\">a</span>, <span class=\"tex-font-style-tt\">b</span> and <span class=\"tex-font-style-tt\">c</span> as the number of occurrences of this character in the string. For example, for string ยซ<span class=\"tex-font-style-tt\">abc</span>ยป: |<span class=\"tex-span\"><i>a</i></span>| = 1, |<span class=\"tex-span\"><i>b</i></span>| = 1, |<span class=\"tex-span\"><i>c</i></span>| = 1, and for string ยซ<span class=\"tex-font-style-tt\">bbc</span>ยป: |<span class=\"tex-span\"><i>a</i></span>| = 0, |<span class=\"tex-span\"><i>b</i></span>| = 2, |<span class=\"tex-span\"><i>c</i></span>| = 1. </p><p>While performing the described operations, Nick sometimes got <span class=\"tex-font-style-underline\">balanced strings</span>. Let's say that a string is balanced, if the frequencies of each character differ by at most 1. That is <span class=\"tex-span\">โ-โ1โโคโ|<i>a</i>|โ-โ|<i>b</i>|โโคโ1</span>, <span class=\"tex-span\">โ-โ1โโคโ|<i>a</i>|โ-โ|<i>c</i>|โโคโ1</span> ะธ <span class=\"tex-span\">โ-โ1โโคโ|<i>b</i>|โ-โ|<i>c</i>|โโคโ1</span>. </p><p>Would you help Nick find the number of different balanced strings that can be obtained by performing the operations described above, perhaps multiple times, on the given string <span class=\"tex-span\"><i>s</i></span>. This number should be calculated modulo <span class=\"tex-span\">51123987</span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ150</span>) โ the length of the given string <span class=\"tex-span\"><i>s</i></span>. Next line contains the given string <span class=\"tex-span\"><i>s</i></span>. The initial string can be balanced as well, in this case it should be counted too. The given string <span class=\"tex-span\"><i>s</i></span> consists only of characters <span class=\"tex-font-style-tt\">a</span>, <span class=\"tex-font-style-tt\">b</span> and <span class=\"tex-font-style-tt\">c</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the only number โ the number of different balanced strings that can be obtained by performing the described operations, perhaps multiple times, on the given string <span class=\"tex-span\"><i>s</i></span>, modulo <span class=\"tex-span\">51123987</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />abca<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />abbc<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />ab<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In the first sample it is possible to get <span class=\"tex-span\">51</span> different strings through the described operations, but only <span class=\"tex-span\">7</span> of them are balanced: ยซ<span class=\"tex-font-style-tt\">abca</span>ยป, ยซ<span class=\"tex-font-style-tt\">bbca</span>ยป, ยซ<span class=\"tex-font-style-tt\">bcca</span>ยป, ยซ<span class=\"tex-font-style-tt\">bcaa</span>ยป, ยซ<span class=\"tex-font-style-tt\">abcc</span>ยป, ยซ<span class=\"tex-font-style-tt\">abbc</span>ยป, ยซ<span class=\"tex-font-style-tt\">aabc</span>ยป. In the second sample: ยซ<span class=\"tex-font-style-tt\">abbc</span>ยป, ยซ<span class=\"tex-font-style-tt\">aabc</span>ยป, ยซ<span class=\"tex-font-style-tt\">abcc</span>ยป. 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='db02a831347ebee346bb8256eecc937c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a>,\r\n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/blog/entry/447\">Contest discussion</a><br /><b><br />Problem A. Noldbach problem<br /><br /></b>To solve this problem you were to find prime numbers in range <span class=\"tex-span\">[2..<i>N</i>]</span>. The constraints were pretty small, so you could do that in any way - using the Sieve of Eratosthenes or simply looping over all possible divisors of a number.<br />Take every pair of neighboring prime numbers and check if their sum increased by <span class=\"tex-span\">1</span> is a prime number too. Count the number of these pairs, compare it to <span class=\"tex-span\"><i>K</i></span> and output the result.<br /><br /><b>Problem B. Hierarchy</b><br /> <br />Note that if employee, except one, has exactly one supervisor, then our hierarchy will be tree-like for sure.<br />For each employee consider all applications in which he appears as a subordinate. If for more than one employee there are no such applications at all, it's obvious that <span class=\"tex-span\">โ-โ1</span> is the answer. In other case, for each employee find such an application with minimal cost and add these costs to get the answer.<br />Alternatively, you could use Kruskal's algorithm finding a minimum spanning tree for a graph. But you should be careful so that you don't assign the second supervisor to some employee.<br />And yes, the employees' qualifications weren't actually needed to solve this problem :)<br /><br /><b>Problem C. Balance<br /></b><br />Consider the input string <span class=\"tex-span\"><i>A</i></span> of length <span class=\"tex-span\"><i>n</i></span>. Let's perform some operations from the problem statement on this string; suppose we obtained some string <span class=\"tex-span\"><i>B</i></span>. Let <i>compression</i> of string <span class=\"tex-span\"><i>X</i></span> be a string <span class=\"tex-span\"><i>X</i>'</span> obtained from <span class=\"tex-span\"><i>X</i></span> by replacing all consecutive equal letters with one such letter. For example, if <span class=\"tex-span\"><i>S</i>โ=โ"<i>aabcccbbaa</i>"</span>, then its compression <span class=\"tex-span\"><i>S</i>'โ=โ"<i>abcba</i>"</span>.<br />Now, consider compressions of strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> - <span class=\"tex-span\"><i>A</i>'</span> and <span class=\"tex-span\"><i>B</i>'</span>. It can be proven that if <span class=\"tex-span\"><i>B</i></span> can be obtained from some string <span class=\"tex-span\"><i>A</i></span> using some number of operations from the problem statement, then <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, and vice versa - if for any strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> of equal length <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, then string <span class=\"tex-span\"><i>B</i></span> can be obtained from string <span class=\"tex-span\"><i>A</i></span> using some number of operations.<br />Intuitively you can understand it in this manner: suppose we use some letter <span class=\"tex-span\"><i>a</i></span> from position <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>A</i></span> in order to put letter <span class=\"tex-span\"><i>a</i></span> at positions <span class=\"tex-span\"><i>j</i>..<i>k</i></span> of <span class=\"tex-span\"><i>B</i></span> (again, using problem statement operations). Then we can't use letters at positions <span class=\"tex-span\">1..<i>i</i>โ-โ1</span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\"><i>k</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>B</i></span> in any way; also, we can't use letters at positions <span class=\"tex-span\"><i>i</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\">1..<i>j</i>โ-โ1</span> of string <span class=\"tex-span\"><i>B</i></span>.<br /><br />Now we have some basis for our solution, which will use dynamic programming. We'll form string <span class=\"tex-span\"><i>B</i></span> letter by letter, considering the fact that <span class=\"tex-span\"><i>B</i>'</span> should still be a subsequence of <span class=\"tex-span\"><i>A</i>'</span> (that is, we'll search for <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> while forming <span class=\"tex-span\"><i>B</i></span>). For this matter we'll keep some position <span class=\"tex-span\"><i>i</i></span> in string <span class=\"tex-span\"><i>A</i>'</span> denoting where we stopped searching <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> at the moment, and three variables <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span>, denoting the frequences of characters <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> respectively in string <span class=\"tex-span\"><i>B</i></span>. Here are the transitions of our DP:<br />1) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>a</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>a</i>'</sub>,โ<i>kA</i>โ+โ1,โ<i>kB</i>,โ<i>kC</i>)</span>.<br />2) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>b</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>b</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>โ+โ1,โ<i>kC</i>)</span>.<br />3) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>c</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>c</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โ+โ1)</span>.<br />Where <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is equal to minimal <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>j</i>โโฅโ<i>i</i></span> and <span class=\"tex-span\"><i>A</i>'<sub class=\"lower-index\"><i>j</i></sub>โ=โ<i>x</i></span> (that is, the nearest occurrence of character <span class=\"tex-span\"><i>x</i></span> in <span class=\"tex-span\"><i>A</i>'</span>, starting from position <span class=\"tex-span\"><i>i</i></span>). Clearly, if in some case <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is undefined, then the corresponding transition is impossible.<br />Having calculated <span class=\"tex-span\"><i>f</i>(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span>, it's easy to find the answer: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c535315cd62cf85c44079a977c735e791f53a1d9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for all triples <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span> for which the balance condition is fulfilled.<br /><br />Such a solution exceeds time and memory limits. Note that if string <span class=\"tex-span\"><i>B</i></span> is going to be balanced, then <span class=\"tex-span\"><i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โโคโ(<i>n</i>โ+โ2)โ/โ3</span>, so the number of states can be reduced up to 27 times. But it's also possible to decrease memory usage much storing matrix <span class=\"tex-span\"><i>f</i></span> by layers, where each layer is given by some value of <span class=\"tex-span\"><i>kA</i></span> (or <span class=\"tex-span\"><i>kB</i></span> or <span class=\"tex-span\"><i>kC</i></span>). It's possible since the value of <span class=\"tex-span\"><i>kA</i></span> is increased either by <span class=\"tex-span\">0</span> or by <span class=\"tex-span\">1</span> in each transition.<br /><br />The overall complexity is <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span> with a quite small constant.<br /><b><br />Problem D. Notepad</b><br /><br />The answer to the problem is <span class=\"tex-span\"><i>b</i><sup class=\"upper-index\"><i>n</i>โ-โ1</sup>โ*โ(<i>b</i>โ-โ1)</span> mod <span class=\"tex-span\"><i>c</i></span>. The main thing you should be able to do in this problem - count the value ofย <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>C</i></span> for some long numbers <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and a short number <span class=\"tex-span\"><i>C</i></span>. Simple exponentiation by squaring exceeds time limit since to converse of <span class=\"tex-span\"><i>B</i></span> to binary you need about <span class=\"tex-span\"><i>O</i>(|<i>B</i>|<sup class=\"upper-index\">2</sup>)</span> operations, where <span class=\"tex-span\">|<i>B</i>|</span> is the number of digits in decimal representation of number <span class=\"tex-span\"><i>B</i></span>.<br />The first thing to do is to transform <span class=\"tex-span\"><i>A</i></span> to <span class=\"tex-span\"><i>A</i></span> mod <span class=\"tex-span\"><i>C</i></span>. It isn't difficult to understand that this transformation doesn't change the answer.<br />Let's represent <span class=\"tex-span\"><i>C</i></span> as <span class=\"tex-span\"><i>C</i>โ=โ<i>p</i><sub class=\"lower-index\">1</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">1</sub></sup><i>p</i><sub class=\"lower-index\">2</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">2</sub></sup>...<i>p</i><sub class=\"lower-index\"><i>m</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>, where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are different prime numbers.<br />Calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for all <span class=\"tex-span\"><i>i</i></span> in the following way. There are two possible cases:<br />1) <span class=\"tex-span\"><i>A</i></span> is not divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are coprime, and you can use <a href=\"https://en.wikipedia.org/wiki/Euler%27s_theorem\">Euler's theorem</a>: <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i>'</sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> (mod <span class=\"tex-span\"><i>C</i></span>), where <span class=\"tex-span\"><i>B</i>'โ=โ<i>B</i></span> mod <span class=\"tex-span\">ฯ(<i>C</i>)</span> and <span class=\"tex-span\">ฯ(<i>C</i>)</span> is Euler's totient function;<br />2) <span class=\"tex-span\"><i>A</i></span> is divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then if <span class=\"tex-span\"><i>B</i>โโฅโ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ0</span>, and if <span class=\"tex-span\"><i>B</i>โ<โ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then you can calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in any way since B is very small.<br />Since all <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> are pairwise coprime you may use <a href=\"https://en.wikipedia.org/wiki/Chinese_remainder_theorem\">chinese remainder theorem</a> to obtain the answer.<br /><br />You can also use Euler's theorem directly. Note that if for some <span class=\"tex-span\"><i>B</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>โโฅโ29</span> you know that <span class=\"tex-span\">|<i>B</i><sub class=\"lower-index\">1</sub>โ-โ<i>B</i><sub class=\"lower-index\">2</sub>|</span> mod <span class=\"tex-span\">ฯ(<i>C</i>)โ=โ0</span>, then all <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> for them will be the same (<span class=\"tex-span\">29</span> is the maximal possible value of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>). Using that you may reduce <span class=\"tex-span\"><i>B</i></span> so that it becomes relatively small and obtain the answer using exponentiation by squaring.<br /><br />There is another solution used by many contestants. Represent <span class=\"tex-span\"><i>B</i></span> as <span class=\"tex-span\"><i>B</i>โ=โ<i>d</i><sub class=\"lower-index\">0</sub>โ+โ10<i>d</i><sub class=\"lower-index\">1</sub>โ+โ10<sup class=\"upper-index\">2</sup><i>d</i><sub class=\"lower-index\">2</sub>โ+โ...โ+โ10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></span>, where <span class=\"tex-span\">0โโคโ<i>d</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ9</span> (in fact <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> is the <span class=\"tex-span\"><i>i</i></span>-th digit of <span class=\"tex-span\"><i>B</i></span> counting from the last). Since <span class=\"tex-span\"><i>a</i><sup class=\"upper-index\"><i>x</i>โ+โ<i>y</i></sup>โ=โ<i>a</i><sup class=\"upper-index\"><i>x</i></sup>ยท <i>a</i><sup class=\"upper-index\"><i>y</i></sup></span>, you know that <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\">0</sub></sup>ยท <i>A</i><sup class=\"upper-index\">10<i>d</i><sub class=\"lower-index\">1</sub></sup>ยท ...ยท <i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>. The values of <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span> can be obtained by successive exponentiation (that is, <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i>โ-โ1</sub><sup class=\"upper-index\">10</sup></span>); if you have <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span>, it's easy to get <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. The answer is the product above (modulo <span class=\"tex-span\"><i>C</i></span>, of course).<br /><br /><b>Problem E. Palisection</b><br /><b><br /></b>The first thing to do is to find all subpalindromes in the given string. For this you may use a beautiful algorithm described for example <a href=\"http://www.akalin.cx/2007/11/28/finding-the-longest-palindromic-substring-in-linear-time/\">here</a>. In short, this algorithm find the maximal length of a subpalindrome with its center either at position <span class=\"tex-span\"><i>i</i></span> of the string or between positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i>โ+โ1</span> for each possible placement of the center.<br />For example, suppose that the maximal subpalindrome length with center at position <span class=\"tex-span\"><i>i</i></span> is <span class=\"tex-span\">5</span>; it means that there are three subpalindromes with center at <span class=\"tex-span\"><i>i</i></span>, with lengths <span class=\"tex-span\">1</span> (<span class=\"tex-span\"><i>i</i>..<i>i</i></span>), <span class=\"tex-span\">3</span> (<span class=\"tex-span\"><i>i</i>โ-โ1..<i>i</i>โ+โ1</span>) and <span class=\"tex-span\">5</span> (<span class=\"tex-span\"><i>i</i>โ-โ2..<i>i</i>โ+โ2</span>). In general, all starting and finishing positions of subpalindromes with a fixed center lie on some interval of positions, which is pretty easy to find.<br />Let's find for each position <span class=\"tex-span\"><i>i</i></span> the value of <span class=\"tex-span\"><i>start</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes starting at position <span class=\"tex-span\"><i>i</i></span>. All these values can be found in linear time. Let's create an auxiliary array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If after processing a position in the string some new pack of subpalindromes was found and they start at positions <span class=\"tex-span\"><i>i</i>..<i>j</i></span>, then increase the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> by <span class=\"tex-span\">1</span>, and decrease the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> by <span class=\"tex-span\">1</span>. Now <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/044b5bba9f36a6f4c4c60731bc951bd5f5502393.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Proving this fact is left as an exercise to the reader :)<br />In a similar way it's possible to calculate <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes finishing at position <span class=\"tex-span\"><i>i</i></span>.<br />Since it's easy to count the total number of subpalindromes, let's find the number of <b>non</b>-intersecting pairs of subpalindromes and subtract this number from the total number of pairs to obtain the answer. Note that if two subpalindromes don't intersect then one of them lies strictly to the left of the other one in the string. Then, the number of non-intersecting pairs of subpalindromes is equal to: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5d386dc072593340d4780c81993c93d11bb5a7a5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /><br />This can be calculated in linear time if the value of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c06dd8724651d1b78ba36f10ed6d42d2e3eb20a6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is recalculated by addition of <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span> before moving from position <span class=\"tex-span\"><i>i</i></span> to position <span class=\"tex-span\"><i>i</i>โ+โ1</span>.<br />The overall complexity of the algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span>.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/17\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 17</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-184-451\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"184\",\n blogEntryId: \"451\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2317\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #17</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=contest\" class=\"tag notice\" style=\"text-decoration: none;\">contest</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+30</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/tourist\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/tourist\">\n tourist\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/451#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/451#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"461\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6342\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 20:47\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6342\" href=\"?#comment-6342\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6342\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6342\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysis. Thank you<span style=\"font-family: verdana , arial , sans-serif;font-size: 12.0px;line-height: 20.0px;\">.</span></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6342 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6342 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6342\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6357\" href=\"?#comment-6357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But what can you say about my solution?</p><p>In fact, it looks like:</p><p>a %= c;</p><p>p = phi(c);</p><p>ans = (a ^ (b % p)) % c;</p><p>if (b >= p && ((a ^ p) % c) == 0)</p><p>ย ย ans = 0;</p><p>Maybe there is some subtle counter-example?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6360\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6360\" href=\"?#comment-6360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What? Are you talking about submit 63341? It's not equivalent to what you wrote.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6360\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6361\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6361\" href=\"?#comment-6361\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6361\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6361\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">If your solution is as you wrote, then I believe it's wrong, at least for the case a = 2, b = 4, c = 12. Your answer is 1 while the correct answer is 2^4 mod 12 = 4.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6361 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6361 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6361\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6363\" commentParentId=\"6361\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6363\" href=\"?#comment-6363\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6361\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6363\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6363\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, of course, my bad memory :)</p><p>a %= c;<br /><br />p = phi(c);<br /><br />ans = (a ^ (b % p)) % c;<br /><br />if (b >= p)</p><p>ย ย ans *= ((a ^ p) % c);</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6363 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6363 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6363\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6366\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6366\" href=\"?#comment-6366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, this is correct. It's almost the same as the second approach described in the analysis (using Euler's theorem directly).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6366\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"509249\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2019 22:30\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-509249\" href=\"?#comment-509249\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"509249\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-509249\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explaine why does this solution work?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-509249 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-509249 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-509249\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6367\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Tactic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Tactic\" title=\"Specialist Tactic\" class=\"rated-user user-cyan\">Tactic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 00:19\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6367\" href=\"?#comment-6367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"3077\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks so much for this analysis! Really appreciated, and I hope you will repeat it in upcoming contests.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6367\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6375\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/removed1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/removed1\" title=\"Expert removed1\" class=\"rated-user user-blue\">removed1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 14:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6375\" href=\"?#comment-6375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In D, simplest generalization of fast exponentiation works well: A^(10*x+y) = (A^10)^x * A^y</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6375\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6391\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/swcai\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/swcai\" title=\"Specialist swcai\" class=\"rated-user user-cyan\">swcai</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 16:22\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6391\" href=\"?#comment-6391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1594\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">No luck on problem C. I used java and got "exceed memory limitation error" when allocating dp[151][52][52][52]. :|</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6391\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6458\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ktuan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/727/avatar/55a648886d2699a9.jpg'/> </a>\n <div><a href=\"/profile/ktuan\" title=\"Master ktuan\" class=\"rated-user user-orange\">ktuan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 05:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6458\" href=\"?#comment-6458\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6458\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6458\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I use dp[kA+kB+kC][151][kA][kB], it sounds worse than your way. However, kA+kB+kC always increases by one in each step of DP, so you can use dp1[151][kA][kB] and dp2[151][kA][kB] instead. It's easy to fit in memory.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6458 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6458 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6458\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6700\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MaxBuzz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/MaxBuzz\" title=\"Candidate Master MaxBuzz\" class=\"rated-user user-violet\">MaxBuzz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 12:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6700\" href=\"?#comment-6700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"85\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You need to allocate a ragged array, like this:<br /><br />int[][][][] dp = new int[151][52][][];<br />for (int i = 0; i < dp.length; ++i) {<br />ย ย ย for (int j = 0; j < 52; ++j) {<br />ย ย ย ย ย ย ย dp[i][j] = new int[52 - j][];<br />ย ย ย ย ย ย ย for (int k = 0; j + k < 52; ++j) {<br />ย ย ย ย ย ย ย ย ย ย ย dp[i][j][k] = new int[52 - j - k];<br />ย ย ย ย ย ย ย }<br />ย ย ย }<br />}<br /><br />This allocates only the elements actually needed by the solution, so fitting in memory limit. <br /><br />C/C++ users may use "full" allocation - unused pages of memory will not be loaded, and ML will not be overcomed. But use it with care - there are some problems (not this one) using "lazy" dynamic programming where it is possible to load all or just too many pages by some tricky tests, even if the number of used cells is acceptable.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6700\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 09:14\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6463\" href=\"?#comment-6463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">A naive 15-line python code gives "runtime error on case 24" on problem D, but I expected something like TLE. What could be the reason for it? I usually code in C++ and I don't know what can cause a runtime error on python.<div>http://pastie.org/private/qsj8vbefe3flrfyuqi6ffq<br /></div><div><br /></div><div>Thank you all!</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6475\" commentParentId=\"6463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 11:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6475\" href=\"?#comment-6475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Stack overflow</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6501\" commentParentId=\"6475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 20:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6501\" href=\"?#comment-6501\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6501\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6501\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Oh, of course. Thank you! I've changed to an iterative function but it gives TL 28 now.<div><a href=\"http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w\">http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w</a><br /></div><div><br /></div><div>I'll try to code the good solution now.</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6501 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6501 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6501\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6477\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/661/avatar/adeb7562762246b4.jpg'/> </a>\n <div><a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" title=\"Candidate Master DDDDDDDDDDDDDDDDDDDDDDDD\" class=\"rated-user user-violet\">DDDDDDDDDDDDDDDDDDDDDDDD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 12:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6477\" href=\"?#comment-6477\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6477\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"661\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6477\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Theย tutorialย is nice.<br />Will you post the tutorialsย for coming contests as well?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6477 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6477 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6477\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8153\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Inf_Zero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Inf_Zero\" title=\"Expert Inf_Zero\" class=\"rated-user user-blue\">Inf_Zero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 16:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8153\" href=\"?#comment-8153\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8153\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4806\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8153\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why can't i view the problem statement in english................................</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8153 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8153 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8153\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10592\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cauchyk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6307/avatar/1be12bd76cca6bd4.jpg'/> </a>\n <div><a href=\"/profile/cauchyk\" title=\"Expert cauchyk\" class=\"rated-user user-blue\">cauchyk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2010 11:13\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10592\" href=\"?#comment-10592\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10592\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"6307\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10592\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysia...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10592 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10592 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10592\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"606285\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/17/2020 14:48\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-606285\" href=\"?#comment-606285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"606285\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"606285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-606285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Blog not visible <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>Unable to parse markup [type=CF_HTML]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-606285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-606285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-606285\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-461\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview461 = true;\r\nvar lastPreviewContent461 = 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":77,"cells":{"problem_id":{"kind":"string","value":"17D"},"contest":{"kind":"string","value":"17"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Notepad"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Notepad</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick is attracted by everything unconventional. He doesn't like decimal number system any more, and he decided to study other number systems. A number system with base <span class=\"tex-span\"><i>b</i></span> caught his attention. Before he starts studying it, he wants to write in his notepad all the numbers of length <span class=\"tex-span\"><i>n</i></span> without leading zeros in this number system. Each page in Nick's notepad has enough space for <span class=\"tex-span\"><i>c</i></span> numbers exactly. Nick writes every suitable number only once, starting with the first clean page and leaving no clean spaces. Nick never writes number <span class=\"tex-span\">0</span> as he has unpleasant memories about zero divide.</p><p>Would you help Nick find out how many numbers will be written on the last page.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The only input line contains three space-separated integers <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>c</i></span> (<span class=\"tex-span\">2โโคโ<i>b</i>โ<โ10<sup class=\"upper-index\">10<sup class=\"upper-index\">6</sup></sup></span>, <span class=\"tex-span\">1โโคโ<i>n</i>โ<โ10<sup class=\"upper-index\">10<sup class=\"upper-index\">6</sup></sup></span>, <span class=\"tex-span\">1โโคโ<i>c</i>โโคโ10<sup class=\"upper-index\">9</sup></span>). You may consider that Nick has infinite patience, endless amount of paper and representations of digits as characters. The numbers doesn't contain leading zeros.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the only line output the amount of numbers written on the same page as the last number.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In both samples there are exactly <span class=\"tex-span\">4</span> numbers of length <span class=\"tex-span\">3</span> in binary number system. In the first sample Nick writes <span class=\"tex-span\">3</span> numbers on the first page and <span class=\"tex-span\">1</span> on the second page. In the second sample all the <span class=\"tex-span\">4</span> numbers can be written on the first page.</p></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"21dd5aec792bdaacbd07a2cabaed9731\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"924de51dea4e325c3899bda42e8b7bd9c6a75d69\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Notepad</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Nick is attracted by everything unconventional. He doesn't like decimal number system any more, and he decided to study other number systems. A number system with base <span class=\"tex-span\"><i>b</i></span> caught his attention. Before he starts studying it, he wants to write in his notepad all the numbers of length <span class=\"tex-span\"><i>n</i></span> without leading zeros in this number system. Each page in Nick's notepad has enough space for <span class=\"tex-span\"><i>c</i></span> numbers exactly. Nick writes every suitable number only once, starting with the first clean page and leaving no clean spaces. Nick never writes number <span class=\"tex-span\">0</span> as he has unpleasant memories about zero divide.</p><p>Would you help Nick find out how many numbers will be written on the last page.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The only input line contains three space-separated integers <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>c</i></span> (<span class=\"tex-span\">2โโคโ<i>b</i>โ<โ10<sup class=\"upper-index\">10<sup class=\"upper-index\">6</sup></sup></span>, <span class=\"tex-span\">1โโคโ<i>n</i>โ<โ10<sup class=\"upper-index\">10<sup class=\"upper-index\">6</sup></sup></span>, <span class=\"tex-span\">1โโคโ<i>c</i>โโคโ10<sup class=\"upper-index\">9</sup></span>). You may consider that Nick has infinite patience, endless amount of paper and representations of digits as characters. The numbers doesn't contain leading zeros.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the only line output the amount of numbers written on the same page as the last number.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1</pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4</pre></div></div></div><div class=\"note\"><div class=\"section-title\">Note</div><p>In both samples there are exactly <span class=\"tex-span\">4</span> numbers of length <span class=\"tex-span\">3</span> in binary number system. In the first sample Nick writes <span class=\"tex-span\">3</span> numbers on the first page and <span class=\"tex-span\">1</span> on the second page. In the second sample all the <span class=\"tex-span\">4</span> numbers can be written on the first page.</p></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='db02a831347ebee346bb8256eecc937c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/tourist\">tourist</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/tourist\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/tourist\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/tourist\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/tourist\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/tourist\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/tourist\">Problemsetting</a></li>\r\n <li><a\r\n href=\"/streams/tourist\">Streams</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/tourist\" style=\"text-decoration:none;color:black !important;\">tourist's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"451\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/451\"> Codeforces Beta Round #17 Tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a>,\r\n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/blog/entry/447\">Contest discussion</a><br /><b><br />Problem A. Noldbach problem<br /><br /></b>To solve this problem you were to find prime numbers in range <span class=\"tex-span\">[2..<i>N</i>]</span>. The constraints were pretty small, so you could do that in any way - using the Sieve of Eratosthenes or simply looping over all possible divisors of a number.<br />Take every pair of neighboring prime numbers and check if their sum increased by <span class=\"tex-span\">1</span> is a prime number too. Count the number of these pairs, compare it to <span class=\"tex-span\"><i>K</i></span> and output the result.<br /><br /><b>Problem B. Hierarchy</b><br /> <br />Note that if employee, except one, has exactly one supervisor, then our hierarchy will be tree-like for sure.<br />For each employee consider all applications in which he appears as a subordinate. If for more than one employee there are no such applications at all, it's obvious that <span class=\"tex-span\">โ-โ1</span> is the answer. In other case, for each employee find such an application with minimal cost and add these costs to get the answer.<br />Alternatively, you could use Kruskal's algorithm finding a minimum spanning tree for a graph. But you should be careful so that you don't assign the second supervisor to some employee.<br />And yes, the employees' qualifications weren't actually needed to solve this problem :)<br /><br /><b>Problem C. Balance<br /></b><br />Consider the input string <span class=\"tex-span\"><i>A</i></span> of length <span class=\"tex-span\"><i>n</i></span>. Let's perform some operations from the problem statement on this string; suppose we obtained some string <span class=\"tex-span\"><i>B</i></span>. Let <i>compression</i> of string <span class=\"tex-span\"><i>X</i></span> be a string <span class=\"tex-span\"><i>X</i>'</span> obtained from <span class=\"tex-span\"><i>X</i></span> by replacing all consecutive equal letters with one such letter. For example, if <span class=\"tex-span\"><i>S</i>โ=โ"<i>aabcccbbaa</i>"</span>, then its compression <span class=\"tex-span\"><i>S</i>'โ=โ"<i>abcba</i>"</span>.<br />Now, consider compressions of strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> - <span class=\"tex-span\"><i>A</i>'</span> and <span class=\"tex-span\"><i>B</i>'</span>. It can be proven that if <span class=\"tex-span\"><i>B</i></span> can be obtained from some string <span class=\"tex-span\"><i>A</i></span> using some number of operations from the problem statement, then <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, and vice versa - if for any strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> of equal length <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, then string <span class=\"tex-span\"><i>B</i></span> can be obtained from string <span class=\"tex-span\"><i>A</i></span> using some number of operations.<br />Intuitively you can understand it in this manner: suppose we use some letter <span class=\"tex-span\"><i>a</i></span> from position <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>A</i></span> in order to put letter <span class=\"tex-span\"><i>a</i></span> at positions <span class=\"tex-span\"><i>j</i>..<i>k</i></span> of <span class=\"tex-span\"><i>B</i></span> (again, using problem statement operations). Then we can't use letters at positions <span class=\"tex-span\">1..<i>i</i>โ-โ1</span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\"><i>k</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>B</i></span> in any way; also, we can't use letters at positions <span class=\"tex-span\"><i>i</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\">1..<i>j</i>โ-โ1</span> of string <span class=\"tex-span\"><i>B</i></span>.<br /><br />Now we have some basis for our solution, which will use dynamic programming. We'll form string <span class=\"tex-span\"><i>B</i></span> letter by letter, considering the fact that <span class=\"tex-span\"><i>B</i>'</span> should still be a subsequence of <span class=\"tex-span\"><i>A</i>'</span> (that is, we'll search for <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> while forming <span class=\"tex-span\"><i>B</i></span>). For this matter we'll keep some position <span class=\"tex-span\"><i>i</i></span> in string <span class=\"tex-span\"><i>A</i>'</span> denoting where we stopped searching <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> at the moment, and three variables <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span>, denoting the frequences of characters <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> respectively in string <span class=\"tex-span\"><i>B</i></span>. Here are the transitions of our DP:<br />1) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>a</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>a</i>'</sub>,โ<i>kA</i>โ+โ1,โ<i>kB</i>,โ<i>kC</i>)</span>.<br />2) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>b</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>b</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>โ+โ1,โ<i>kC</i>)</span>.<br />3) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>c</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>c</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โ+โ1)</span>.<br />Where <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is equal to minimal <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>j</i>โโฅโ<i>i</i></span> and <span class=\"tex-span\"><i>A</i>'<sub class=\"lower-index\"><i>j</i></sub>โ=โ<i>x</i></span> (that is, the nearest occurrence of character <span class=\"tex-span\"><i>x</i></span> in <span class=\"tex-span\"><i>A</i>'</span>, starting from position <span class=\"tex-span\"><i>i</i></span>). Clearly, if in some case <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is undefined, then the corresponding transition is impossible.<br />Having calculated <span class=\"tex-span\"><i>f</i>(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span>, it's easy to find the answer: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c535315cd62cf85c44079a977c735e791f53a1d9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for all triples <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span> for which the balance condition is fulfilled.<br /><br />Such a solution exceeds time and memory limits. Note that if string <span class=\"tex-span\"><i>B</i></span> is going to be balanced, then <span class=\"tex-span\"><i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โโคโ(<i>n</i>โ+โ2)โ/โ3</span>, so the number of states can be reduced up to 27 times. But it's also possible to decrease memory usage much storing matrix <span class=\"tex-span\"><i>f</i></span> by layers, where each layer is given by some value of <span class=\"tex-span\"><i>kA</i></span> (or <span class=\"tex-span\"><i>kB</i></span> or <span class=\"tex-span\"><i>kC</i></span>). It's possible since the value of <span class=\"tex-span\"><i>kA</i></span> is increased either by <span class=\"tex-span\">0</span> or by <span class=\"tex-span\">1</span> in each transition.<br /><br />The overall complexity is <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span> with a quite small constant.<br /><b><br />Problem D. Notepad</b><br /><br />The answer to the problem is <span class=\"tex-span\"><i>b</i><sup class=\"upper-index\"><i>n</i>โ-โ1</sup>โ*โ(<i>b</i>โ-โ1)</span> mod <span class=\"tex-span\"><i>c</i></span>. The main thing you should be able to do in this problem - count the value ofย <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>C</i></span> for some long numbers <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and a short number <span class=\"tex-span\"><i>C</i></span>. Simple exponentiation by squaring exceeds time limit since to converse of <span class=\"tex-span\"><i>B</i></span> to binary you need about <span class=\"tex-span\"><i>O</i>(|<i>B</i>|<sup class=\"upper-index\">2</sup>)</span> operations, where <span class=\"tex-span\">|<i>B</i>|</span> is the number of digits in decimal representation of number <span class=\"tex-span\"><i>B</i></span>.<br />The first thing to do is to transform <span class=\"tex-span\"><i>A</i></span> to <span class=\"tex-span\"><i>A</i></span> mod <span class=\"tex-span\"><i>C</i></span>. It isn't difficult to understand that this transformation doesn't change the answer.<br />Let's represent <span class=\"tex-span\"><i>C</i></span> as <span class=\"tex-span\"><i>C</i>โ=โ<i>p</i><sub class=\"lower-index\">1</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">1</sub></sup><i>p</i><sub class=\"lower-index\">2</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">2</sub></sup>...<i>p</i><sub class=\"lower-index\"><i>m</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>, where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are different prime numbers.<br />Calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for all <span class=\"tex-span\"><i>i</i></span> in the following way. There are two possible cases:<br />1) <span class=\"tex-span\"><i>A</i></span> is not divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are coprime, and you can use <a href=\"https://en.wikipedia.org/wiki/Euler%27s_theorem\">Euler's theorem</a>: <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i>'</sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> (mod <span class=\"tex-span\"><i>C</i></span>), where <span class=\"tex-span\"><i>B</i>'โ=โ<i>B</i></span> mod <span class=\"tex-span\">ฯ(<i>C</i>)</span> and <span class=\"tex-span\">ฯ(<i>C</i>)</span> is Euler's totient function;<br />2) <span class=\"tex-span\"><i>A</i></span> is divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then if <span class=\"tex-span\"><i>B</i>โโฅโ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ0</span>, and if <span class=\"tex-span\"><i>B</i>โ<โ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then you can calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in any way since B is very small.<br />Since all <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> are pairwise coprime you may use <a href=\"https://en.wikipedia.org/wiki/Chinese_remainder_theorem\">chinese remainder theorem</a> to obtain the answer.<br /><br />You can also use Euler's theorem directly. Note that if for some <span class=\"tex-span\"><i>B</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>โโฅโ29</span> you know that <span class=\"tex-span\">|<i>B</i><sub class=\"lower-index\">1</sub>โ-โ<i>B</i><sub class=\"lower-index\">2</sub>|</span> mod <span class=\"tex-span\">ฯ(<i>C</i>)โ=โ0</span>, then all <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> for them will be the same (<span class=\"tex-span\">29</span> is the maximal possible value of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>). Using that you may reduce <span class=\"tex-span\"><i>B</i></span> so that it becomes relatively small and obtain the answer using exponentiation by squaring.<br /><br />There is another solution used by many contestants. Represent <span class=\"tex-span\"><i>B</i></span> as <span class=\"tex-span\"><i>B</i>โ=โ<i>d</i><sub class=\"lower-index\">0</sub>โ+โ10<i>d</i><sub class=\"lower-index\">1</sub>โ+โ10<sup class=\"upper-index\">2</sup><i>d</i><sub class=\"lower-index\">2</sub>โ+โ...โ+โ10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></span>, where <span class=\"tex-span\">0โโคโ<i>d</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ9</span> (in fact <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> is the <span class=\"tex-span\"><i>i</i></span>-th digit of <span class=\"tex-span\"><i>B</i></span> counting from the last). Since <span class=\"tex-span\"><i>a</i><sup class=\"upper-index\"><i>x</i>โ+โ<i>y</i></sup>โ=โ<i>a</i><sup class=\"upper-index\"><i>x</i></sup>ยท <i>a</i><sup class=\"upper-index\"><i>y</i></sup></span>, you know that <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\">0</sub></sup>ยท <i>A</i><sup class=\"upper-index\">10<i>d</i><sub class=\"lower-index\">1</sub></sup>ยท ...ยท <i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>. The values of <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span> can be obtained by successive exponentiation (that is, <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i>โ-โ1</sub><sup class=\"upper-index\">10</sup></span>); if you have <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span>, it's easy to get <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. The answer is the product above (modulo <span class=\"tex-span\"><i>C</i></span>, of course).<br /><br /><b>Problem E. Palisection</b><br /><b><br /></b>The first thing to do is to find all subpalindromes in the given string. For this you may use a beautiful algorithm described for example <a href=\"http://www.akalin.cx/2007/11/28/finding-the-longest-palindromic-substring-in-linear-time/\">here</a>. In short, this algorithm find the maximal length of a subpalindrome with its center either at position <span class=\"tex-span\"><i>i</i></span> of the string or between positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i>โ+โ1</span> for each possible placement of the center.<br />For example, suppose that the maximal subpalindrome length with center at position <span class=\"tex-span\"><i>i</i></span> is <span class=\"tex-span\">5</span>; it means that there are three subpalindromes with center at <span class=\"tex-span\"><i>i</i></span>, with lengths <span class=\"tex-span\">1</span> (<span class=\"tex-span\"><i>i</i>..<i>i</i></span>), <span class=\"tex-span\">3</span> (<span class=\"tex-span\"><i>i</i>โ-โ1..<i>i</i>โ+โ1</span>) and <span class=\"tex-span\">5</span> (<span class=\"tex-span\"><i>i</i>โ-โ2..<i>i</i>โ+โ2</span>). In general, all starting and finishing positions of subpalindromes with a fixed center lie on some interval of positions, which is pretty easy to find.<br />Let's find for each position <span class=\"tex-span\"><i>i</i></span> the value of <span class=\"tex-span\"><i>start</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes starting at position <span class=\"tex-span\"><i>i</i></span>. All these values can be found in linear time. Let's create an auxiliary array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If after processing a position in the string some new pack of subpalindromes was found and they start at positions <span class=\"tex-span\"><i>i</i>..<i>j</i></span>, then increase the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> by <span class=\"tex-span\">1</span>, and decrease the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> by <span class=\"tex-span\">1</span>. Now <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/044b5bba9f36a6f4c4c60731bc951bd5f5502393.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Proving this fact is left as an exercise to the reader :)<br />In a similar way it's possible to calculate <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes finishing at position <span class=\"tex-span\"><i>i</i></span>.<br />Since it's easy to count the total number of subpalindromes, let's find the number of <b>non</b>-intersecting pairs of subpalindromes and subtract this number from the total number of pairs to obtain the answer. Note that if two subpalindromes don't intersect then one of them lies strictly to the left of the other one in the string. Then, the number of non-intersecting pairs of subpalindromes is equal to: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5d386dc072593340d4780c81993c93d11bb5a7a5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /><br />This can be calculated in linear time if the value of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c06dd8724651d1b78ba36f10ed6d42d2e3eb20a6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is recalculated by addition of <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span> before moving from position <span class=\"tex-span\"><i>i</i></span> to position <span class=\"tex-span\"><i>i</i>โ+โ1</span>.<br />The overall complexity of the algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span>.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/17\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 17</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-184-451\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"184\",\n blogEntryId: \"451\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2317\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #17</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=contest\" class=\"tag notice\" style=\"text-decoration: none;\">contest</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+30</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/tourist\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/tourist\">\n tourist\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/451#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/451#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"461\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6342\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 20:47\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6342\" href=\"?#comment-6342\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6342\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6342\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysis. Thank you<span style=\"font-family: verdana , arial , sans-serif;font-size: 12.0px;line-height: 20.0px;\">.</span></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6342 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6342 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6342\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6357\" href=\"?#comment-6357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But what can you say about my solution?</p><p>In fact, it looks like:</p><p>a %= c;</p><p>p = phi(c);</p><p>ans = (a ^ (b % p)) % c;</p><p>if (b >= p && ((a ^ p) % c) == 0)</p><p>ย ย ans = 0;</p><p>Maybe there is some subtle counter-example?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6360\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6360\" href=\"?#comment-6360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What? Are you talking about submit 63341? It's not equivalent to what you wrote.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6360\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6361\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6361\" href=\"?#comment-6361\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6361\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6361\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">If your solution is as you wrote, then I believe it's wrong, at least for the case a = 2, b = 4, c = 12. Your answer is 1 while the correct answer is 2^4 mod 12 = 4.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6361 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6361 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6361\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6363\" commentParentId=\"6361\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6363\" href=\"?#comment-6363\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6361\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6363\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6363\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, of course, my bad memory :)</p><p>a %= c;<br /><br />p = phi(c);<br /><br />ans = (a ^ (b % p)) % c;<br /><br />if (b >= p)</p><p>ย ย ans *= ((a ^ p) % c);</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6363 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6363 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6363\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6366\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6366\" href=\"?#comment-6366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, this is correct. It's almost the same as the second approach described in the analysis (using Euler's theorem directly).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6366\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"509249\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2019 22:30\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-509249\" href=\"?#comment-509249\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"509249\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-509249\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explaine why does this solution work?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-509249 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-509249 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-509249\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6367\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Tactic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Tactic\" title=\"Specialist Tactic\" class=\"rated-user user-cyan\">Tactic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 00:19\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6367\" href=\"?#comment-6367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"3077\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks so much for this analysis! Really appreciated, and I hope you will repeat it in upcoming contests.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6367\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6375\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/removed1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/removed1\" title=\"Expert removed1\" class=\"rated-user user-blue\">removed1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 14:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6375\" href=\"?#comment-6375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In D, simplest generalization of fast exponentiation works well: A^(10*x+y) = (A^10)^x * A^y</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6375\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6391\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/swcai\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/swcai\" title=\"Specialist swcai\" class=\"rated-user user-cyan\">swcai</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 16:22\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6391\" href=\"?#comment-6391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1594\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">No luck on problem C. I used java and got "exceed memory limitation error" when allocating dp[151][52][52][52]. :|</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6391\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6458\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ktuan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/727/avatar/55a648886d2699a9.jpg'/> </a>\n <div><a href=\"/profile/ktuan\" title=\"Master ktuan\" class=\"rated-user user-orange\">ktuan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 05:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6458\" href=\"?#comment-6458\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6458\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6458\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I use dp[kA+kB+kC][151][kA][kB], it sounds worse than your way. However, kA+kB+kC always increases by one in each step of DP, so you can use dp1[151][kA][kB] and dp2[151][kA][kB] instead. It's easy to fit in memory.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6458 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6458 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6458\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6700\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MaxBuzz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/MaxBuzz\" title=\"Candidate Master MaxBuzz\" class=\"rated-user user-violet\">MaxBuzz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 12:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6700\" href=\"?#comment-6700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"85\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You need to allocate a ragged array, like this:<br /><br />int[][][][] dp = new int[151][52][][];<br />for (int i = 0; i < dp.length; ++i) {<br />ย ย ย for (int j = 0; j < 52; ++j) {<br />ย ย ย ย ย ย ย dp[i][j] = new int[52 - j][];<br />ย ย ย ย ย ย ย for (int k = 0; j + k < 52; ++j) {<br />ย ย ย ย ย ย ย ย ย ย ย dp[i][j][k] = new int[52 - j - k];<br />ย ย ย ย ย ย ย }<br />ย ย ย }<br />}<br /><br />This allocates only the elements actually needed by the solution, so fitting in memory limit. <br /><br />C/C++ users may use "full" allocation - unused pages of memory will not be loaded, and ML will not be overcomed. But use it with care - there are some problems (not this one) using "lazy" dynamic programming where it is possible to load all or just too many pages by some tricky tests, even if the number of used cells is acceptable.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6700\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 09:14\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6463\" href=\"?#comment-6463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">A naive 15-line python code gives "runtime error on case 24" on problem D, but I expected something like TLE. What could be the reason for it? I usually code in C++ and I don't know what can cause a runtime error on python.<div>http://pastie.org/private/qsj8vbefe3flrfyuqi6ffq<br /></div><div><br /></div><div>Thank you all!</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6475\" commentParentId=\"6463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 11:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6475\" href=\"?#comment-6475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Stack overflow</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6501\" commentParentId=\"6475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 20:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6501\" href=\"?#comment-6501\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6501\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6501\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Oh, of course. Thank you! I've changed to an iterative function but it gives TL 28 now.<div><a href=\"http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w\">http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w</a><br /></div><div><br /></div><div>I'll try to code the good solution now.</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6501 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6501 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6501\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6477\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/661/avatar/adeb7562762246b4.jpg'/> </a>\n <div><a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" title=\"Candidate Master DDDDDDDDDDDDDDDDDDDDDDDD\" class=\"rated-user user-violet\">DDDDDDDDDDDDDDDDDDDDDDDD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 12:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6477\" href=\"?#comment-6477\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6477\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"661\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6477\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Theย tutorialย is nice.<br />Will you post the tutorialsย for coming contests as well?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6477 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6477 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6477\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8153\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Inf_Zero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Inf_Zero\" title=\"Expert Inf_Zero\" class=\"rated-user user-blue\">Inf_Zero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 16:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8153\" href=\"?#comment-8153\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8153\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4806\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8153\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why can't i view the problem statement in english................................</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8153 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8153 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8153\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10592\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cauchyk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6307/avatar/1be12bd76cca6bd4.jpg'/> </a>\n <div><a href=\"/profile/cauchyk\" title=\"Expert cauchyk\" class=\"rated-user user-blue\">cauchyk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2010 11:13\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10592\" href=\"?#comment-10592\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10592\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"6307\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10592\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysia...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10592 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10592 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10592\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"606285\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/17/2020 14:48\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-606285\" href=\"?#comment-606285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"606285\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"606285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-606285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Blog not visible <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>Unable to parse markup [type=CF_HTML]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-606285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-606285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-606285\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-461\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":78,"cells":{"problem_id":{"kind":"string","value":"17E"},"contest":{"kind":"string","value":"17"},"problem":{"kind":"string","value":"E"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"E. Palisection"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Palisection</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In an English class Nick had nothing to do at all, and remembered about wonderful strings called <span class=\"tex-font-style-underline\">palindromes</span>. We should remind you that a string is called a palindrome if it can be read the same way both from left to right and from right to left. Here are examples of such strings: ยซ<span class=\"tex-font-style-tt\">eye</span>ยป, ยซ<span class=\"tex-font-style-tt\">pop</span>ยป, ยซ<span class=\"tex-font-style-tt\">level</span>ยป, ยซ<span class=\"tex-font-style-tt\">aba</span>ยป, ยซ<span class=\"tex-font-style-tt\">deed</span>ยป, ยซ<span class=\"tex-font-style-tt\">racecar</span>ยป, ยซ<span class=\"tex-font-style-tt\">rotor</span>ยป, ยซ<span class=\"tex-font-style-tt\">madam</span>ยป. </p><p>Nick started to look carefully for all palindromes in the text that they were reading in the class. For each occurrence of each palindrome in the text he wrote a pair โ the position of the beginning and the position of the ending of this occurrence in the text. Nick called each occurrence of each palindrome he found in the text <span class=\"tex-font-style-underline\">subpalindrome</span>. When he found all the subpalindromes, he decided to find out how many different pairs among these subpalindromes cross. Two subpalindromes cross if they cover common positions in the text. No palindrome can cross itself.</p><p>Let's look at the actions, performed by Nick, by the example of text ยซ<span class=\"tex-font-style-tt\">babb</span>ยป. At first he wrote out all subpalindromes:</p><center>โข ยซ<span class=\"tex-font-style-tt\">b</span>ยป โ <span class=\"tex-span\">1..1</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">bab</span>ยป โ <span class=\"tex-span\">1..3</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">a</span>ยป โ <span class=\"tex-span\">2..2</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">b</span>ยป โ <span class=\"tex-span\">3..3</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">bb</span>ยป โ <span class=\"tex-span\">3..4</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">b</span>ยป โ <span class=\"tex-span\">4..4</span> </center><p>Then Nick counted the amount of different pairs among these subpalindromes that cross. These pairs were six:</p><center> <span class=\"tex-font-style-tt\">1.</span> <span class=\"tex-span\">1..1</span> cross with <span class=\"tex-span\">1..3</span> </center><center> <span class=\"tex-font-style-tt\">2.</span> <span class=\"tex-span\">1..3</span> cross with <span class=\"tex-span\">2..2</span> </center><center> <span class=\"tex-font-style-tt\">3.</span> <span class=\"tex-span\">1..3</span> cross with <span class=\"tex-span\">3..3</span> </center><center> <span class=\"tex-font-style-tt\">4.</span> <span class=\"tex-span\">1..3</span> cross with <span class=\"tex-span\">3..4</span> </center><center> <span class=\"tex-font-style-tt\">5.</span> <span class=\"tex-span\">3..3</span> cross with <span class=\"tex-span\">3..4</span> </center><center> <span class=\"tex-font-style-tt\">6.</span> <span class=\"tex-span\">3..4</span> cross with <span class=\"tex-span\">4..4</span> </center><p>Since it's very exhausting to perform all the described actions manually, Nick asked you to help him and write a program that can find out the amount of different subpalindrome pairs that cross. Two subpalindrome pairs are regarded as different if one of the pairs contains a subpalindrome that the other does not.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2ยท10<sup class=\"upper-index\">6</sup></span>) โ length of the text. The following line contains <span class=\"tex-span\"><i>n</i></span> lower-case Latin letters (from <span class=\"tex-font-style-tt\">a</span> to <span class=\"tex-font-style-tt\">z</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the only line output the amount of different pairs of two subpalindromes that cross each other. Output the answer modulo <span class=\"tex-span\">51123987</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>babb<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>aa<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"30bd80e906a93a808a58c9100cc59e00\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"924de51dea4e325c3899bda42e8b7bd9c6a75d69\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/17\">Codeforces Beta Round 17</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='30bd80e906a93a808a58c9100cc59e00'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/17/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Prefix- and Z-functions, suffix structures, KnuthโMorrisโPratt algorithm, etc\">\r\n strings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='30bd80e906a93a808a58c9100cc59e00'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"80\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='30bd80e906a93a808a58c9100cc59e00'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"80\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/447\" title=\"Codeforces Beta Round #17\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"98:99\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/451\" title=\"Codeforces Beta Round #17 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"444:445\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: 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class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Palisection</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In an English class Nick had nothing to do at all, and remembered about wonderful strings called <span class=\"tex-font-style-underline\">palindromes</span>. We should remind you that a string is called a palindrome if it can be read the same way both from left to right and from right to left. Here are examples of such strings: ยซ<span class=\"tex-font-style-tt\">eye</span>ยป, ยซ<span class=\"tex-font-style-tt\">pop</span>ยป, ยซ<span class=\"tex-font-style-tt\">level</span>ยป, ยซ<span class=\"tex-font-style-tt\">aba</span>ยป, ยซ<span class=\"tex-font-style-tt\">deed</span>ยป, ยซ<span class=\"tex-font-style-tt\">racecar</span>ยป, ยซ<span class=\"tex-font-style-tt\">rotor</span>ยป, ยซ<span class=\"tex-font-style-tt\">madam</span>ยป. </p><p>Nick started to look carefully for all palindromes in the text that they were reading in the class. For each occurrence of each palindrome in the text he wrote a pair โ the position of the beginning and the position of the ending of this occurrence in the text. Nick called each occurrence of each palindrome he found in the text <span class=\"tex-font-style-underline\">subpalindrome</span>. When he found all the subpalindromes, he decided to find out how many different pairs among these subpalindromes cross. Two subpalindromes cross if they cover common positions in the text. No palindrome can cross itself.</p><p>Let's look at the actions, performed by Nick, by the example of text ยซ<span class=\"tex-font-style-tt\">babb</span>ยป. At first he wrote out all subpalindromes:</p><center>โข ยซ<span class=\"tex-font-style-tt\">b</span>ยป โ <span class=\"tex-span\">1..1</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">bab</span>ยป โ <span class=\"tex-span\">1..3</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">a</span>ยป โ <span class=\"tex-span\">2..2</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">b</span>ยป โ <span class=\"tex-span\">3..3</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">bb</span>ยป โ <span class=\"tex-span\">3..4</span> </center><center>โข ยซ<span class=\"tex-font-style-tt\">b</span>ยป โ <span class=\"tex-span\">4..4</span> </center><p>Then Nick counted the amount of different pairs among these subpalindromes that cross. These pairs were six:</p><center> <span class=\"tex-font-style-tt\">1.</span> <span class=\"tex-span\">1..1</span> cross with <span class=\"tex-span\">1..3</span> </center><center> <span class=\"tex-font-style-tt\">2.</span> <span class=\"tex-span\">1..3</span> cross with <span class=\"tex-span\">2..2</span> </center><center> <span class=\"tex-font-style-tt\">3.</span> <span class=\"tex-span\">1..3</span> cross with <span class=\"tex-span\">3..3</span> </center><center> <span class=\"tex-font-style-tt\">4.</span> <span class=\"tex-span\">1..3</span> cross with <span class=\"tex-span\">3..4</span> </center><center> <span class=\"tex-font-style-tt\">5.</span> <span class=\"tex-span\">3..3</span> cross with <span class=\"tex-span\">3..4</span> </center><center> <span class=\"tex-font-style-tt\">6.</span> <span class=\"tex-span\">3..4</span> cross with <span class=\"tex-span\">4..4</span> </center><p>Since it's very exhausting to perform all the described actions manually, Nick asked you to help him and write a program that can find out the amount of different subpalindrome pairs that cross. Two subpalindrome pairs are regarded as different if one of the pairs contains a subpalindrome that the other does not.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2ยท10<sup class=\"upper-index\">6</sup></span>) โ length of the text. The following line contains <span class=\"tex-span\"><i>n</i></span> lower-case Latin letters (from <span class=\"tex-font-style-tt\">a</span> to <span class=\"tex-font-style-tt\">z</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the only line output the amount of different pairs of two subpalindromes that cross each other. Output the answer modulo <span class=\"tex-span\">51123987</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />babb<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />aa<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='db02a831347ebee346bb8256eecc937c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a>,\r\n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/blog/entry/447\">Contest discussion</a><br /><b><br />Problem A. Noldbach problem<br /><br /></b>To solve this problem you were to find prime numbers in range <span class=\"tex-span\">[2..<i>N</i>]</span>. The constraints were pretty small, so you could do that in any way - using the Sieve of Eratosthenes or simply looping over all possible divisors of a number.<br />Take every pair of neighboring prime numbers and check if their sum increased by <span class=\"tex-span\">1</span> is a prime number too. Count the number of these pairs, compare it to <span class=\"tex-span\"><i>K</i></span> and output the result.<br /><br /><b>Problem B. Hierarchy</b><br /> <br />Note that if employee, except one, has exactly one supervisor, then our hierarchy will be tree-like for sure.<br />For each employee consider all applications in which he appears as a subordinate. If for more than one employee there are no such applications at all, it's obvious that <span class=\"tex-span\">โ-โ1</span> is the answer. In other case, for each employee find such an application with minimal cost and add these costs to get the answer.<br />Alternatively, you could use Kruskal's algorithm finding a minimum spanning tree for a graph. But you should be careful so that you don't assign the second supervisor to some employee.<br />And yes, the employees' qualifications weren't actually needed to solve this problem :)<br /><br /><b>Problem C. Balance<br /></b><br />Consider the input string <span class=\"tex-span\"><i>A</i></span> of length <span class=\"tex-span\"><i>n</i></span>. Let's perform some operations from the problem statement on this string; suppose we obtained some string <span class=\"tex-span\"><i>B</i></span>. Let <i>compression</i> of string <span class=\"tex-span\"><i>X</i></span> be a string <span class=\"tex-span\"><i>X</i>'</span> obtained from <span class=\"tex-span\"><i>X</i></span> by replacing all consecutive equal letters with one such letter. For example, if <span class=\"tex-span\"><i>S</i>โ=โ"<i>aabcccbbaa</i>"</span>, then its compression <span class=\"tex-span\"><i>S</i>'โ=โ"<i>abcba</i>"</span>.<br />Now, consider compressions of strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> - <span class=\"tex-span\"><i>A</i>'</span> and <span class=\"tex-span\"><i>B</i>'</span>. It can be proven that if <span class=\"tex-span\"><i>B</i></span> can be obtained from some string <span class=\"tex-span\"><i>A</i></span> using some number of operations from the problem statement, then <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, and vice versa - if for any strings <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> of equal length <span class=\"tex-span\"><i>B</i>'</span> is a subsequence of <span class=\"tex-span\"><i>A</i>'</span>, then string <span class=\"tex-span\"><i>B</i></span> can be obtained from string <span class=\"tex-span\"><i>A</i></span> using some number of operations.<br />Intuitively you can understand it in this manner: suppose we use some letter <span class=\"tex-span\"><i>a</i></span> from position <span class=\"tex-span\"><i>i</i></span> of <span class=\"tex-span\"><i>A</i></span> in order to put letter <span class=\"tex-span\"><i>a</i></span> at positions <span class=\"tex-span\"><i>j</i>..<i>k</i></span> of <span class=\"tex-span\"><i>B</i></span> (again, using problem statement operations). Then we can't use letters at positions <span class=\"tex-span\">1..<i>i</i>โ-โ1</span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\"><i>k</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>B</i></span> in any way; also, we can't use letters at positions <span class=\"tex-span\"><i>i</i>โ+โ1..<i>n</i></span> of string <span class=\"tex-span\"><i>A</i></span> in order to influence positions <span class=\"tex-span\">1..<i>j</i>โ-โ1</span> of string <span class=\"tex-span\"><i>B</i></span>.<br /><br />Now we have some basis for our solution, which will use dynamic programming. We'll form string <span class=\"tex-span\"><i>B</i></span> letter by letter, considering the fact that <span class=\"tex-span\"><i>B</i>'</span> should still be a subsequence of <span class=\"tex-span\"><i>A</i>'</span> (that is, we'll search for <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> while forming <span class=\"tex-span\"><i>B</i></span>). For this matter we'll keep some position <span class=\"tex-span\"><i>i</i></span> in string <span class=\"tex-span\"><i>A</i>'</span> denoting where we stopped searching <span class=\"tex-span\"><i>B</i>'</span> in <span class=\"tex-span\"><i>A</i>'</span> at the moment, and three variables <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span>, denoting the frequences of characters <span class=\"tex-span\"><i>a</i></span>, <span class=\"tex-span\"><i>b</i></span>, <span class=\"tex-span\"><i>c</i></span> respectively in string <span class=\"tex-span\"><i>B</i></span>. Here are the transitions of our DP:<br />1) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>a</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>a</i>'</sub>,โ<i>kA</i>โ+โ1,โ<i>kB</i>,โ<i>kC</i>)</span>.<br />2) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>b</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>b</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>โ+โ1,โ<i>kC</i>)</span>.<br />3) The next character of string <span class=\"tex-span\"><i>B</i></span> is <span class=\"tex-span\"><i>c</i></span>. Then we may go from the state <span class=\"tex-span\">(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span> to the state <span class=\"tex-span\">(<i>next</i><sub class=\"lower-index\"><i>i</i>,โ'<i>c</i>'</sub>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โ+โ1)</span>.<br />Where <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is equal to minimal <span class=\"tex-span\"><i>j</i></span> such that <span class=\"tex-span\"><i>j</i>โโฅโ<i>i</i></span> and <span class=\"tex-span\"><i>A</i>'<sub class=\"lower-index\"><i>j</i></sub>โ=โ<i>x</i></span> (that is, the nearest occurrence of character <span class=\"tex-span\"><i>x</i></span> in <span class=\"tex-span\"><i>A</i>'</span>, starting from position <span class=\"tex-span\"><i>i</i></span>). Clearly, if in some case <span class=\"tex-span\"><i>next</i><sub class=\"lower-index\"><i>i</i>,โ<i>x</i></sub></span> is undefined, then the corresponding transition is impossible.<br />Having calculated <span class=\"tex-span\"><i>f</i>(<i>i</i>,โ<i>kA</i>,โ<i>kB</i>,โ<i>kC</i>)</span>, it's easy to find the answer: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c535315cd62cf85c44079a977c735e791f53a1d9.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> for all triples <span class=\"tex-span\"><i>kA</i></span>, <span class=\"tex-span\"><i>kB</i></span>, <span class=\"tex-span\"><i>kC</i></span> for which the balance condition is fulfilled.<br /><br />Such a solution exceeds time and memory limits. Note that if string <span class=\"tex-span\"><i>B</i></span> is going to be balanced, then <span class=\"tex-span\"><i>kA</i>,โ<i>kB</i>,โ<i>kC</i>โโคโ(<i>n</i>โ+โ2)โ/โ3</span>, so the number of states can be reduced up to 27 times. But it's also possible to decrease memory usage much storing matrix <span class=\"tex-span\"><i>f</i></span> by layers, where each layer is given by some value of <span class=\"tex-span\"><i>kA</i></span> (or <span class=\"tex-span\"><i>kB</i></span> or <span class=\"tex-span\"><i>kC</i></span>). It's possible since the value of <span class=\"tex-span\"><i>kA</i></span> is increased either by <span class=\"tex-span\">0</span> or by <span class=\"tex-span\">1</span> in each transition.<br /><br />The overall complexity is <span class=\"tex-span\"><i>O</i>(<i>N</i><sup class=\"upper-index\">4</sup>)</span> with a quite small constant.<br /><b><br />Problem D. Notepad</b><br /><br />The answer to the problem is <span class=\"tex-span\"><i>b</i><sup class=\"upper-index\"><i>n</i>โ-โ1</sup>โ*โ(<i>b</i>โ-โ1)</span> mod <span class=\"tex-span\"><i>c</i></span>. The main thing you should be able to do in this problem - count the value ofย <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>C</i></span> for some long numbers <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>B</i></span> and a short number <span class=\"tex-span\"><i>C</i></span>. Simple exponentiation by squaring exceeds time limit since to converse of <span class=\"tex-span\"><i>B</i></span> to binary you need about <span class=\"tex-span\"><i>O</i>(|<i>B</i>|<sup class=\"upper-index\">2</sup>)</span> operations, where <span class=\"tex-span\">|<i>B</i>|</span> is the number of digits in decimal representation of number <span class=\"tex-span\"><i>B</i></span>.<br />The first thing to do is to transform <span class=\"tex-span\"><i>A</i></span> to <span class=\"tex-span\"><i>A</i></span> mod <span class=\"tex-span\"><i>C</i></span>. It isn't difficult to understand that this transformation doesn't change the answer.<br />Let's represent <span class=\"tex-span\"><i>C</i></span> as <span class=\"tex-span\"><i>C</i>โ=โ<i>p</i><sub class=\"lower-index\">1</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">1</sub></sup><i>p</i><sub class=\"lower-index\">2</sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\">2</sub></sup>...<i>p</i><sub class=\"lower-index\"><i>m</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>, where <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are different prime numbers.<br />Calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> for all <span class=\"tex-span\"><i>i</i></span> in the following way. There are two possible cases:<br />1) <span class=\"tex-span\"><i>A</i></span> is not divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then <span class=\"tex-span\"><i>A</i></span> and <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span> are coprime, and you can use <a href=\"https://en.wikipedia.org/wiki/Euler%27s_theorem\">Euler's theorem</a>: <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i>'</sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> (mod <span class=\"tex-span\"><i>C</i></span>), where <span class=\"tex-span\"><i>B</i>'โ=โ<i>B</i></span> mod <span class=\"tex-span\">ฯ(<i>C</i>)</span> and <span class=\"tex-span\">ฯ(<i>C</i>)</span> is Euler's totient function;<br />2) <span class=\"tex-span\"><i>A</i></span> is divisible by <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub></span>: then if <span class=\"tex-span\"><i>B</i>โโฅโ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\"><i>B</i></sup></span> mod <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ0</span>, and if <span class=\"tex-span\"><i>B</i>โ<โ<i>k</i><sub class=\"lower-index\"><i>i</i></sub></span> then you can calculate <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in any way since B is very small.<br />Since all <span class=\"tex-span\"><i>p</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></sup></span> are pairwise coprime you may use <a href=\"https://en.wikipedia.org/wiki/Chinese_remainder_theorem\">chinese remainder theorem</a> to obtain the answer.<br /><br />You can also use Euler's theorem directly. Note that if for some <span class=\"tex-span\"><i>B</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>โโฅโ29</span> you know that <span class=\"tex-span\">|<i>B</i><sub class=\"lower-index\">1</sub>โ-โ<i>B</i><sub class=\"lower-index\">2</sub>|</span> mod <span class=\"tex-span\">ฯ(<i>C</i>)โ=โ0</span>, then all <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> for them will be the same (<span class=\"tex-span\">29</span> is the maximal possible value of <span class=\"tex-span\"><i>k</i><sub class=\"lower-index\"><i>i</i></sub></span>). Using that you may reduce <span class=\"tex-span\"><i>B</i></span> so that it becomes relatively small and obtain the answer using exponentiation by squaring.<br /><br />There is another solution used by many contestants. Represent <span class=\"tex-span\"><i>B</i></span> as <span class=\"tex-span\"><i>B</i>โ=โ<i>d</i><sub class=\"lower-index\">0</sub>โ+โ10<i>d</i><sub class=\"lower-index\">1</sub>โ+โ10<sup class=\"upper-index\">2</sup><i>d</i><sub class=\"lower-index\">2</sub>โ+โ...โ+โ10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></span>, where <span class=\"tex-span\">0โโคโ<i>d</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ9</span> (in fact <span class=\"tex-span\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></span> is the <span class=\"tex-span\"><i>i</i></span>-th digit of <span class=\"tex-span\"><i>B</i></span> counting from the last). Since <span class=\"tex-span\"><i>a</i><sup class=\"upper-index\"><i>x</i>โ+โ<i>y</i></sup>โ=โ<i>a</i><sup class=\"upper-index\"><i>x</i></sup>ยท <i>a</i><sup class=\"upper-index\"><i>y</i></sup></span>, you know that <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\"><i>B</i></sup>โ=โ<i>A</i><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\">0</sub></sup>ยท <i>A</i><sup class=\"upper-index\">10<i>d</i><sub class=\"lower-index\">1</sub></sup>ยท ...ยท <i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>m</i></sup><i>d</i><sub class=\"lower-index\"><i>m</i></sub></sup></span>. The values of <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span> can be obtained by successive exponentiation (that is, <span class=\"tex-span\"><i>u</i><sub class=\"lower-index\"><i>i</i></sub>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i>โ-โ1</sub><sup class=\"upper-index\">10</sup></span>); if you have <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup></sup></span>, it's easy to get <span class=\"tex-span\"><i>A</i><sup class=\"upper-index\">10<sup class=\"upper-index\"><i>i</i></sup><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup>โ=โ<i>u</i><sub class=\"lower-index\"><i>i</i></sub><sup class=\"upper-index\"><i>d</i><sub class=\"lower-index\"><i>i</i></sub></sup></span>. The answer is the product above (modulo <span class=\"tex-span\"><i>C</i></span>, of course).<br /><br /><b>Problem E. Palisection</b><br /><b><br /></b>The first thing to do is to find all subpalindromes in the given string. For this you may use a beautiful algorithm described for example <a href=\"http://www.akalin.cx/2007/11/28/finding-the-longest-palindromic-substring-in-linear-time/\">here</a>. In short, this algorithm find the maximal length of a subpalindrome with its center either at position <span class=\"tex-span\"><i>i</i></span> of the string or between positions <span class=\"tex-span\"><i>i</i></span> and <span class=\"tex-span\"><i>i</i>โ+โ1</span> for each possible placement of the center.<br />For example, suppose that the maximal subpalindrome length with center at position <span class=\"tex-span\"><i>i</i></span> is <span class=\"tex-span\">5</span>; it means that there are three subpalindromes with center at <span class=\"tex-span\"><i>i</i></span>, with lengths <span class=\"tex-span\">1</span> (<span class=\"tex-span\"><i>i</i>..<i>i</i></span>), <span class=\"tex-span\">3</span> (<span class=\"tex-span\"><i>i</i>โ-โ1..<i>i</i>โ+โ1</span>) and <span class=\"tex-span\">5</span> (<span class=\"tex-span\"><i>i</i>โ-โ2..<i>i</i>โ+โ2</span>). In general, all starting and finishing positions of subpalindromes with a fixed center lie on some interval of positions, which is pretty easy to find.<br />Let's find for each position <span class=\"tex-span\"><i>i</i></span> the value of <span class=\"tex-span\"><i>start</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes starting at position <span class=\"tex-span\"><i>i</i></span>. All these values can be found in linear time. Let's create an auxiliary array <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>. If after processing a position in the string some new pack of subpalindromes was found and they start at positions <span class=\"tex-span\"><i>i</i>..<i>j</i></span>, then increase the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span> by <span class=\"tex-span\">1</span>, and decrease the value of <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>j</i>โ+โ1</sub></span> by <span class=\"tex-span\">1</span>. Now <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/044b5bba9f36a6f4c4c60731bc951bd5f5502393.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" />. Proving this fact is left as an exercise to the reader :)<br />In a similar way it's possible to calculate <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span>, which is equal to the number of subpalindromes finishing at position <span class=\"tex-span\"><i>i</i></span>.<br />Since it's easy to count the total number of subpalindromes, let's find the number of <b>non</b>-intersecting pairs of subpalindromes and subtract this number from the total number of pairs to obtain the answer. Note that if two subpalindromes don't intersect then one of them lies strictly to the left of the other one in the string. Then, the number of non-intersecting pairs of subpalindromes is equal to: <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/5d386dc072593340d4780c81993c93d11bb5a7a5.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /><br />This can be calculated in linear time if the value of <img align=\"middle\" class=\"tex-formula\" src=\"https://espresso.codeforces.com/c06dd8724651d1b78ba36f10ed6d42d2e3eb20a6.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /> is recalculated by addition of <span class=\"tex-span\"><i>finish</i><sub class=\"lower-index\"><i>i</i></sub></span> before moving from position <span class=\"tex-span\"><i>i</i></span> to position <span class=\"tex-span\"><i>i</i>โ+โ1</span>.<br />The overall complexity of the algorithm is <span class=\"tex-span\"><i>O</i>(<i>N</i>)</span>.</div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/17\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 17</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-184-451\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"184\",\n blogEntryId: \"451\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2317\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #17</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=codeforces\" class=\"tag notice\" style=\"text-decoration: none;\">codeforces</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=contest\" class=\"tag notice\" style=\"text-decoration: none;\">contest</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+30</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-451\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/tourist\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/tourist\">\n tourist\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/11/2010 00:43\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/451#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/451#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"461\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (19)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6342\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/hacker007\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/hacker007\" title=\"Specialist hacker007\" class=\"rated-user user-cyan\">hacker007</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 20:47\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6342\" href=\"?#comment-6342\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6342\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"2067\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6342\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysis. Thank you<span style=\"font-family: verdana , arial , sans-serif;font-size: 12.0px;line-height: 20.0px;\">.</span></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6342 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6342 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6342\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6357\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6357\" href=\"?#comment-6357\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6357\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6357\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>But what can you say about my solution?</p><p>In fact, it looks like:</p><p>a %= c;</p><p>p = phi(c);</p><p>ans = (a ^ (b % p)) % c;</p><p>if (b >= p && ((a ^ p) % c) == 0)</p><p>ย ย ans = 0;</p><p>Maybe there is some subtle counter-example?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6357 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6357 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6357\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6360\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6360\" href=\"?#comment-6360\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6360\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6360\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">What? Are you talking about submit 63341? It's not equivalent to what you wrote.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6360 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6360 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6360\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6361\" commentParentId=\"6357\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6361\" href=\"?#comment-6361\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6357\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6361\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6361\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">If your solution is as you wrote, then I believe it's wrong, at least for the case a = 2, b = 4, c = 12. Your answer is 1 while the correct answer is 2^4 mod 12 = 4.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6361 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6361 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6361\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6363\" commentParentId=\"6361\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/e-maxx\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/298/avatar/5bd7a2f4eb79f03c.jpg'/> </a>\n <div><a href=\"/profile/e-maxx\" title=\"International Master e-maxx\" class=\"rated-user user-orange\">e-maxx</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:31\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6363\" href=\"?#comment-6363\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6361\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6363\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"298\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6363\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Ah, of course, my bad memory :)</p><p>a %= c;<br /><br />p = phi(c);<br /><br />ans = (a ^ (b % p)) % c;<br /><br />if (b >= p)</p><p>ย ย ans *= ((a ^ p) % c);</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6363 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6363 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6363\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6366\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/tourist\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/422/avatar/2b5dbe87f0d859a2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/11/2010 23:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6366\" href=\"?#comment-6366\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6366\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"422\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6366\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Yes, this is correct. It's almost the same as the second approach described in the analysis (using Euler's theorem directly).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6366 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6366 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6366\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"509249\" commentParentId=\"6363\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/BaturaDima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/BaturaDima\" title=\"Candidate Master BaturaDima\" class=\"rated-user user-violet\">BaturaDima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/02/2019 22:30\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-509249\" href=\"?#comment-509249\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6363\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"509249\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"12055\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-509249\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Can anyone explaine why does this solution work?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-509249 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-509249 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-509249\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6367\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Tactic\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Tactic\" title=\"Specialist Tactic\" class=\"rated-user user-cyan\">Tactic</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 00:19\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6367\" href=\"?#comment-6367\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6367\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"13\"\r\n data-commentUserId=\"3077\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6367\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks so much for this analysis! Really appreciated, and I hope you will repeat it in upcoming contests.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6367 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6367 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6367\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6375\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/removed1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/removed1\" title=\"Expert removed1\" class=\"rated-user user-blue\">removed1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 14:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6375\" href=\"?#comment-6375\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6375\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"66\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6375\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In D, simplest generalization of fast exponentiation works well: A^(10*x+y) = (A^10)^x * A^y</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6375 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6375 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6375\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6391\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/swcai\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/swcai\" title=\"Specialist swcai\" class=\"rated-user user-cyan\">swcai</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/12/2010 16:22\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6391\" href=\"?#comment-6391\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6391\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1594\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6391\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">No luck on problem C. I used java and got "exceed memory limitation error" when allocating dp[151][52][52][52]. :|</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6391 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6391 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6391\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6458\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ktuan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/727/avatar/55a648886d2699a9.jpg'/> </a>\n <div><a href=\"/profile/ktuan\" title=\"Master ktuan\" class=\"rated-user user-orange\">ktuan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 05:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6458\" href=\"?#comment-6458\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6458\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"727\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6458\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I use dp[kA+kB+kC][151][kA][kB], it sounds worse than your way. However, kA+kB+kC always increases by one in each step of DP, so you can use dp1[151][kA][kB] and dp2[151][kA][kB] instead. It's easy to fit in memory.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6458 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6458 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6458\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6700\" commentParentId=\"6391\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MaxBuzz\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/MaxBuzz\" title=\"Candidate Master MaxBuzz\" class=\"rated-user user-violet\">MaxBuzz</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 12:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6700\" href=\"?#comment-6700\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6391\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6700\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"85\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6700\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You need to allocate a ragged array, like this:<br /><br />int[][][][] dp = new int[151][52][][];<br />for (int i = 0; i < dp.length; ++i) {<br />ย ย ย for (int j = 0; j < 52; ++j) {<br />ย ย ย ย ย ย ย dp[i][j] = new int[52 - j][];<br />ย ย ย ย ย ย ย for (int k = 0; j + k < 52; ++j) {<br />ย ย ย ย ย ย ย ย ย ย ย dp[i][j][k] = new int[52 - j - k];<br />ย ย ย ย ย ย ย }<br />ย ย ย }<br />}<br /><br />This allocates only the elements actually needed by the solution, so fitting in memory limit. <br /><br />C/C++ users may use "full" allocation - unused pages of memory will not be loaded, and ML will not be overcomed. But use it with care - there are some problems (not this one) using "lazy" dynamic programming where it is possible to load all or just too many pages by some tricky tests, even if the number of used cells is acceptable.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6700 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6700 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6700\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6463\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 09:14\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6463\" href=\"?#comment-6463\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6463\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6463\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">A naive 15-line python code gives "runtime error on case 24" on problem D, but I expected something like TLE. What could be the reason for it? I usually code in C++ and I don't know what can cause a runtime error on python.<div>http://pastie.org/private/qsj8vbefe3flrfyuqi6ffq<br /></div><div><br /></div><div>Thank you all!</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6463 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6463 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6463\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6475\" commentParentId=\"6463\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 11:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6475\" href=\"?#comment-6475\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6463\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6475\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6475\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Stack overflow</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6475 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6475 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6475\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6501\" commentParentId=\"6475\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 20:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6501\" href=\"?#comment-6501\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6475\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6501\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6501\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Oh, of course. Thank you! I've changed to an iterative function but it gives TL 28 now.<div><a href=\"http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w\">http://pastie.org/private/fuzrqd2vcaetxm8fcz7x8w</a><br /></div><div><br /></div><div>I'll try to code the good solution now.</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6501 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6501 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6501\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6477\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/661/avatar/adeb7562762246b4.jpg'/> </a>\n <div><a href=\"/profile/DDDDDDDDDDDDDDDDDDDDDDDD\" title=\"Candidate Master DDDDDDDDDDDDDDDDDDDDDDDD\" class=\"rated-user user-violet\">DDDDDDDDDDDDDDDDDDDDDDDD</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/13/2010 12:20\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6477\" href=\"?#comment-6477\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6477\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"661\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6477\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Theย tutorialย is nice.<br />Will you post the tutorialsย for coming contests as well?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6477 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6477 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6477\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8153\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Inf_Zero\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Inf_Zero\" title=\"Expert Inf_Zero\" class=\"rated-user user-blue\">Inf_Zero</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 16:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8153\" href=\"?#comment-8153\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8153\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4806\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8153\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why can't i view the problem statement in english................................</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8153 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8153 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8153\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"10592\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cauchyk\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/6307/avatar/1be12bd76cca6bd4.jpg'/> </a>\n <div><a href=\"/profile/cauchyk\" title=\"Expert cauchyk\" class=\"rated-user user-blue\">cauchyk</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/17/2010 11:13\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-10592\" href=\"?#comment-10592\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"10592\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"6307\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-10592\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Excellent analysia...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-10592 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-10592 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-10592\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"606285\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/apoorva222g\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213778/avatar/2153e9cce1fd37f.jpg'/> </a>\n <div><a href=\"/profile/apoorva222g\" title=\"Expert apoorva222g\" class=\"rated-user user-blue\">apoorva222g</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Apr/17/2020 14:48\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-606285\" href=\"?#comment-606285\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n <span style=\"\" commentId=\"606285\" revisionCount=\"2\" revision=\"2\">\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;color:#bebebe;\" class=\"leftRevision\">←</a>\r\n Rev. <span class=\"revision\">2</span>\r\n <a href=\"#\" style=\"text-decoration:none;font-size:1.4rem;visibility:hidden;color:#bebebe;\" class=\"rightRevision\">→</a>\r\n </span>\r\n \r\n\r\n<span commentid=\"606285\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213778\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-606285\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Blog not visible <a class=\"rated-user user-legendary\" href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></p><p>Unable to parse markup [type=CF_HTML]</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-606285 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-606285 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-606285\">\r\n </ul>\r\n</div>\r\n <br/>\r\n\r\n<div id=\"editBox-461\" style=\"width:50em;display:none;\">\r\n <div class=\"previewBody\" style=\"border: 1px solid #d4d4d4; margin-bottom: 0.5em; padding: 0.25em; display:none;\"> </div>\r\n <div style=\"width: 1px\"> </div>\r\n <div class=\"commentLocale\" style=\"position: relative; top: 0.5em;left:4px;display: none;\">\r\n <input type=\"radio\" name=\"locale\" value=\"en\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In English</span>\r\n <input style=\"margin-left:1em\" type=\"radio\" name=\"locale\" value=\"ru\"><span style=\"font-size: 1.2rem;position: relative; bottom: 3px;\">In Russian</span>\r\n </div>\r\n <textarea data-drafts-id=\"CommentReplyFrame\" class=\"wysiwyg\" name=\"editContent\" rows=\"20\" style=\"width:99%;\"></textarea>\r\n <div class=\"error error__content\"></div>\r\n <div style=\"text-align:center;\">\r\n <input type=\"button\" name=\"preview\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Preview\"/>\r\n <input type=\"button\" name=\"save\" style=\"padding: 0.25em 1em; margin-top: 1em; min-width: 6.5em;\" value=\"Save\"/>\r\n </div>\r\n</div>\r\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n\r\nvar firstPreview461 = true;\r\nvar lastPreviewContent461 = 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"}}},{"rowIdx":79,"cells":{"problem_id":{"kind":"string","value":"18A"},"contest":{"kind":"string","value":"18"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Triangle"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Triangle</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>At a geometry lesson Bob learnt that a triangle is called right-angled if it is nondegenerate and one of its angles is right. Bob decided to draw such a triangle immediately: on a sheet of paper he drew three points with integer coordinates, and joined them with segments of straight lines, then he showed the triangle to Peter. Peter said that Bob's triangle is not right-angled, but is <span class=\"tex-font-style-underline\">almost</span> right-angled: the triangle itself is not right-angled, but it is possible to move one of the points exactly by distance 1 so, that all the coordinates remain integer, and the triangle become right-angled. Bob asks you to help him and find out if Peter tricks him. By the given coordinates of the triangle you should find out if it is right-angled, almost right-angled, or neither of these.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 6 space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>,โ<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>,โ<i>x</i><sub class=\"lower-index\">3</sub>,โ<i>y</i><sub class=\"lower-index\">3</sub></span> โ coordinates of the triangle's vertices. All the coordinates are integer and don't exceed 100 in absolute value. It's guaranteed that the triangle is nondegenerate, i.e. its total area is not zero.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the given triangle is right-angled, output <span class=\"tex-font-style-tt\">RIGHT</span>, if it is almost right-angled, output <span class=\"tex-font-style-tt\">ALMOST</span>, and if it is neither of these, output <span class=\"tex-font-style-tt\">NEITHER</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>0 0 2 0 0 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>RIGHT<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 4 5 6 6<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NEITHER<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>-1 0 2 0 0 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>ALMOST<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"c781445b6d909d491720a1860bdfdc22\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"8911200f14aef28f115e91000f02f60f9dc6c961\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_c63baa9e153e89c68a164f1af915cd1ad62f55bf\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Triangle</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>At a geometry lesson Bob learnt that a triangle is called right-angled if it is nondegenerate and one of its angles is right. Bob decided to draw such a triangle immediately: on a sheet of paper he drew three points with integer coordinates, and joined them with segments of straight lines, then he showed the triangle to Peter. Peter said that Bob's triangle is not right-angled, but is <span class=\"tex-font-style-underline\">almost</span> right-angled: the triangle itself is not right-angled, but it is possible to move one of the points exactly by distance 1 so, that all the coordinates remain integer, and the triangle become right-angled. Bob asks you to help him and find out if Peter tricks him. By the given coordinates of the triangle you should find out if it is right-angled, almost right-angled, or neither of these.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 6 space-separated integers <span class=\"tex-span\"><i>x</i><sub class=\"lower-index\">1</sub>,โ<i>y</i><sub class=\"lower-index\">1</sub>,โ<i>x</i><sub class=\"lower-index\">2</sub>,โ<i>y</i><sub class=\"lower-index\">2</sub>,โ<i>x</i><sub class=\"lower-index\">3</sub>,โ<i>y</i><sub class=\"lower-index\">3</sub></span> โ coordinates of the triangle's vertices. All the coordinates are integer and don't exceed 100 in absolute value. It's guaranteed that the triangle is nondegenerate, i.e. its total area is not zero.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the given triangle is right-angled, output <span class=\"tex-font-style-tt\">RIGHT</span>, if it is almost right-angled, output <span class=\"tex-font-style-tt\">ALMOST</span>, and if it is neither of these, output <span class=\"tex-font-style-tt\">NEITHER</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>0 0 2 0 0 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>RIGHT<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2 3 4 5 6 6<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NEITHER<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>-1 0 2 0 0 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>ALMOST<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n $problem.find(\".diff-notifier\").hide();\r\n });\r\n\r\n $problem.find(\"a.view-changes\").click(function() {\r\n $.post(\"/data/diff\", {action: \"getDiff\", a: previousStatementText, b: statementText}, function (result) {\r\n if (result[\"success\"] === \"true\") {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" 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class=\"rated-user user-violet\">ArtDitel</a>,\r\n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/462\">Contest discussion</a></p><h3>Problem ะ. Triangle</h3><p><u>Pythagorean theorem, brute force</u></p><p>In this problem you should implement a function, which takes three points and checks whether they form a right-angled triangle. There are a lot of ways to do so, but the simplest one is using a Pythagorean theorem.</p><p> </p><p>You should use squared distances instead of taking roots to overcome problems related to precision errors.</p><p>To examine a triangle on almost-rightness, you can try to move each point in each of four possible directions and check the new triangle using our function. It's good and easy to use two arrays: dx={-1,0,1,0} and dy={0,1,0,-1} for moving. Then we can get the new coordinates of shifted point simply using the following code:<br /></p><blockquote>for (int i = 0; i < 4; i ++)</blockquote><blockquote>{</blockquote><blockquote><blockquote>int x = dx[i] + px;</blockquote></blockquote><blockquote><blockquote>int y = dy[i] + py;</blockquote></blockquote><blockquote><p>}</p></blockquote><h3>Problem B. Platforms</h3><p><u>Simulation</u></p><p>Illustrative picture:</p><p><img src=\"https://s40.radikal.ru/i089/1006/10/c50af7e13d4d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>In this problem you were to determine a coordinate where the grasshoper would fall down. To do so, let's keep the position of grasshoper at a certain moment of time.<br />To avoid TLE one should "move" the grasshoper along a platform in <em>O(1)</em> time (not in the cycle). The grasshoper will do <em>j = (right<sub>i</sub>-x)/d</em> jumps along platform "<em>i</em>", where <em>x</em> is the grasshoper's coordinate (he's standing at the platform), and <em>right<sub>i</sub></em> is a right coordinate of the platform. So we can move the grasshoper on <em>j*d</em> to the right at once.</p><h3> Problem C. Stripe<br /></h3><p><u>Brute force</u><br /></p><p>One should keep two sums S1 ans S2, where S1 is the sum of all numbers on the left part of the stripe, and S2 is the sum of the right one. At the beginning S1 = 0 and S2 equals to the sum of all numbers of the stripe. Then we move the border of the parts within a cycle from left to right recalculating the values of S1 and S2 each iteration and increasing the answer when it's necessary.<br /></p><h3>Problem D. Seller Bob<br /></h3><p><u>Greedy, long arithmetics</u><br /></p><p>In this problem we need big integers because the number 2<sup>2000</sup> doesn't fit in int64.<br />We are given an assertion that for every memory stick there will be at most one potential customer. Since 2<sup>xย </sup>> 2<sup>x-1</sup> + 2<sup>x-2</sup> + ... 2<sup>0</sup>, the earnings of selling the most expensive stick will be greater than the earnings of selling all other sticks. So we first try to sell the most expensive stick, then the second one and so on. So one should try to sell sticks in descending order of their costs.<br /></p><h3> Probelm E. Flag 2<br /></h3><p><u>Dynamic programming</u><br /></p><p>In this problem one should use dynamic programming. Consider the function <em>DP(level, A, B)</em> (where <em>A</em> and <em>B</em> are the numbers of colors, from 0 to 25), which returns the minimal number of repaintings required to repaint the first level rows. The last row will be like <em>ABABAB...</em><br /></p><p>Consider recalculating of this function. First, calculate the number of repaintings required for row <em>level</em> to be like <em>ABABAB...</em> (let <em>D</em> will be this number). Obviously, the row can be painted so if the color of the first element of the previous row is not "<em>A</em>" and the second one - not "<em>B</em>" (it's a condition of adjacent cells not to have the same color) or it should be the first row. So <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25, i != j, i != B, j != A.</em><br /><br />Estimate the run time of our program: <em>O(N*26*26*(M+26*26))</em>, this value is smaller than <em>4*10<sup>8</sup></em><br /></p><p><em><sup><br /></sup></em></p><p><strong>Great t</strong><strong>hanks to <a href=\"https://codeforces.com/profile/OBepkJIokEP\">Ilya Akolzin</a> for his help in ย translation</strong><em><sup><br /></sup></em></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/18\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 18 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-201-463\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"201\",\n blogEntryId: \"463\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2318\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #18</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+34</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/ArtDitel\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/ArtDitel\">\n ArtDitel\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/463#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/463#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"473\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (17)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6681\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 00:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6681\" href=\"?#comment-6681\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6681\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6681\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In problem B you can also make the first <span class=\"tex-span\"><i>m</i></span> steps, and if after them the grasshopper didn't fall, it means that he'll fall only after all <span class=\"tex-span\"><i>n</i></span> platforms</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6681 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6681 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6681\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6704\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wbdyni344\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1732/avatar/b910042564e945ad.jpg'/> </a>\n <div><a href=\"/profile/wbdyni344\" title=\"Expert wbdyni344\" class=\"rated-user user-blue\">wbdyni344</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6704\" href=\"?#comment-6704\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6704\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6704\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Solution of problem E is not fast enough to pass it .I've tried to solve it by this alg. but still got TLE.<br />Anyone has a faster alg ?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6704 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6704 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6704\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6705\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:56\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6705\" href=\"?#comment-6705\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6705\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6705\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">It was mentioned that it passes in C++, but not Java.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6705 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6705 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6705\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6710\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6710\" href=\"?#comment-6710\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6710\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6710\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you use Java for this problem, "dumb" solution (with constraint 26^4 for DP step) will get TLE. I wrote more complicated solution, where we count minimal value of recolorings in previous line, with which we can go to specified coloring of current line). This way we can get smaller constraint, cause we can sort values, and check only two of them.</p><p>If you want, you can check my solution (submission 70276), where I've implemented this algorithm.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6710 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6710 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6710\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6721\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:53\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6721\" href=\"?#comment-6721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Actually, dumb solution passes with pretty easy optimisation for java - for each step we will count number of recolorings needed for given color to be on odd position and same for even. This leads O(nm * 26^2 + n * 26^4) "dumb" solution to be O(nm * 26 + n * 26^4) which passes. See my solution for implimentation</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6721\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6751\" commentParentId=\"6721\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:11\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6751\" href=\"?#comment-6751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6721\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I have solution with this asymptotic, and it got TL. Unfortynately, I haven't find your solution, maybe something wrong with my eyes =)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6752\" commentParentId=\"6751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6752\" href=\"?#comment-6752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/contest/18/status/E?order=BY_ARRIVED_ASC\">Here it is</a>ย (5th row)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6764\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/giongto35\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/giongto35\" title=\"Candidate Master giongto35\" class=\"rated-user user-violet\">giongto35</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 09:01\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6764\" href=\"?#comment-6764\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6764\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1772\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6764\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">why so complex?<br />I solved it easily . I save position had minimum value in previous step , it's POS1 , POS2 , DP[level,POS1,POS2] is minimum . In the next step , <em>DP(level, A, B) = </em><em>DP(level-1, POS1, POS2) + D if (POS1<>A) and (POS2 <> B) <br /></em>Else <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25,</em></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6764 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6764 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6764\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6833\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 19:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6833\" href=\"?#comment-6833\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6833\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6833\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I determine all possible checkerings of the the the previous row, and then sort them by non-decreasing cost. Then, for every checkering in the next row, just find the one with lowest cost that is compatible from the row above. This ends up being about O(n^2 log n) where n is ~650 = 26*25. This is less than 4,000,000.<br /><br />After doing a few rounds of this competition though, I'm tired of solutions working in C and not Java :( Slower languages should be given more time (even like, 25% more, though it should probably be closer to 50%), or the time limit should just be larger. The ACM-ICPC does this.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6833 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6833 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6833\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6708\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MciprianM\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3547/avatar/2e9cc229295dcb51.jpg'/> </a>\n <div><a href=\"/profile/MciprianM\" title=\"Expert MciprianM\" class=\"rated-user user-blue\">MciprianM</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 14:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6708\" href=\"?#comment-6708\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6708\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3547\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6708\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you help me with WA on test 25 problem D?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6708 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6708 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6708\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6714\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/fobnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3058/avatar/7723159acb0bf919.jpg'/> </a>\n <div><a href=\"/profile/fobnn\" title=\"Expert fobnn\" class=\"rated-user user-blue\">fobnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 16:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6714\" href=\"?#comment-6714\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6714\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3058\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6714\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">think you!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6714 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6714 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6714\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6722\" commentParentId=\"6714\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6722\" href=\"?#comment-6722\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6714\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6722\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6722\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">That reminds me of:<div>-SOS! We are sinking!</div><div>-What are you thinking about?</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6722 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6722 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6722\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6956\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 09:44\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6956\" href=\"?#comment-6956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D: problem statement says that<br />"A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. " <br />I am unable to understand this.. suppose for example<br /><pre>5<br />win 10<br />win 5<br />sell 5<br />win 1<br />sell 10</pre>in this bob should sell 2^5 to 1st customer because he have memory of that size..<br />orย he will not sell to that customer and keep 2^10 memory to sell 2nd customer.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6966\" commentParentId=\"6956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 10:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6966\" href=\"?#comment-6966\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6966\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6966\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">He sold 2^5 to the 1st customer, but now he wants to know what was the optimal way to sell memory sticks, and for that he should have kept 2^10.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6966 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6966 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6966\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6976\" commentParentId=\"6966\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6976\" href=\"?#comment-6976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6966\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thank you for explaining ....<br />i completely misunderstood during contest...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 23:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7034\" href=\"?#comment-7034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />Is there any way to know the input because i have got WA so many times...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7107\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2010 21:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7107\" href=\"?#comment-7107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7107\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />someone please look at my code (71593 ) and tell me error i have tried lot to find out.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Platforms"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Platforms</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In one one-dimensional world there are <span class=\"tex-span\"><i>n</i></span> platforms. Platform with index <span class=\"tex-span\"><i>k</i></span> (platforms are numbered from 1) is a segment with coordinates <span class=\"tex-span\">[(<i>k</i>โ-โ1)<i>m</i>,โ(<i>k</i>โ-โ1)<i>m</i>โ+โ<i>l</i>]</span>, and <span class=\"tex-span\"><i>l</i>โ<โ<i>m</i></span>. Grasshopper Bob starts to jump along the platforms from point <span class=\"tex-span\">0</span>, with each jump he moves exactly <span class=\"tex-span\"><i>d</i></span> units right. Find out the coordinate of the point, where Bob will fall down. The grasshopper falls down, if he finds himself not on the platform, but if he finds himself on the edge of the platform, he doesn't fall down.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 4 integer numbers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>l</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>d</i>,โ<i>m</i>,โ<i>l</i>โโคโ10<sup class=\"upper-index\">6</sup>,โ<i>l</i>โ<โ<i>m</i></span>) โ respectively: amount of platforms, length of the grasshopper Bob's jump, and numbers <span class=\"tex-span\"><i>m</i></span> and <span class=\"tex-span\"><i>l</i></span> needed to find coordinates of the <span class=\"tex-span\"><i>k</i></span>-th platform: <span class=\"tex-span\">[(<i>k</i>โ-โ1)<i>m</i>,โ(<i>k</i>โ-โ1)<i>m</i>โ+โ<i>l</i>]</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the coordinates of the point, where the grosshopper will fall down. Don't forget that if Bob finds himself on the platform edge, he doesn't fall down.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2 5 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 4 11 8<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>20<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"30f3cb23da328a3f62da5938d30233d0\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"8911200f14aef28f115e91000f02f60f9dc6c961\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Platforms</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>In one one-dimensional world there are <span class=\"tex-span\"><i>n</i></span> platforms. Platform with index <span class=\"tex-span\"><i>k</i></span> (platforms are numbered from 1) is a segment with coordinates <span class=\"tex-span\">[(<i>k</i>โ-โ1)<i>m</i>,โ(<i>k</i>โ-โ1)<i>m</i>โ+โ<i>l</i>]</span>, and <span class=\"tex-span\"><i>l</i>โ<โ<i>m</i></span>. Grasshopper Bob starts to jump along the platforms from point <span class=\"tex-span\">0</span>, with each jump he moves exactly <span class=\"tex-span\"><i>d</i></span> units right. Find out the coordinate of the point, where Bob will fall down. The grasshopper falls down, if he finds himself not on the platform, but if he finds himself on the edge of the platform, he doesn't fall down.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 4 integer numbers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>d</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>l</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>d</i>,โ<i>m</i>,โ<i>l</i>โโคโ10<sup class=\"upper-index\">6</sup>,โ<i>l</i>โ<โ<i>m</i></span>) โ respectively: amount of platforms, length of the grasshopper Bob's jump, and numbers <span class=\"tex-span\"><i>m</i></span> and <span class=\"tex-span\"><i>l</i></span> needed to find coordinates of the <span class=\"tex-span\"><i>k</i></span>-th platform: <span class=\"tex-span\">[(<i>k</i>โ-โ1)<i>m</i>,โ(<i>k</i>โ-โ1)<i>m</i>โ+โ<i>l</i>]</span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the coordinates of the point, where the grosshopper will fall down. Don't forget that if Bob finds himself on the platform edge, he doesn't fall down.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2 2 5 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 4 11 8<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>20<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:26</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" 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class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='f8524db49153144b45c3d5e056bc183c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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class=\"rated-user user-violet\">ArtDitel</a>,\r\n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/462\">Contest discussion</a></p><h3>Problem ะ. Triangle</h3><p><u>Pythagorean theorem, brute force</u></p><p>In this problem you should implement a function, which takes three points and checks whether they form a right-angled triangle. There are a lot of ways to do so, but the simplest one is using a Pythagorean theorem.</p><p> </p><p>You should use squared distances instead of taking roots to overcome problems related to precision errors.</p><p>To examine a triangle on almost-rightness, you can try to move each point in each of four possible directions and check the new triangle using our function. It's good and easy to use two arrays: dx={-1,0,1,0} and dy={0,1,0,-1} for moving. Then we can get the new coordinates of shifted point simply using the following code:<br /></p><blockquote>for (int i = 0; i < 4; i ++)</blockquote><blockquote>{</blockquote><blockquote><blockquote>int x = dx[i] + px;</blockquote></blockquote><blockquote><blockquote>int y = dy[i] + py;</blockquote></blockquote><blockquote><p>}</p></blockquote><h3>Problem B. Platforms</h3><p><u>Simulation</u></p><p>Illustrative picture:</p><p><img src=\"https://s40.radikal.ru/i089/1006/10/c50af7e13d4d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>In this problem you were to determine a coordinate where the grasshoper would fall down. To do so, let's keep the position of grasshoper at a certain moment of time.<br />To avoid TLE one should "move" the grasshoper along a platform in <em>O(1)</em> time (not in the cycle). The grasshoper will do <em>j = (right<sub>i</sub>-x)/d</em> jumps along platform "<em>i</em>", where <em>x</em> is the grasshoper's coordinate (he's standing at the platform), and <em>right<sub>i</sub></em> is a right coordinate of the platform. So we can move the grasshoper on <em>j*d</em> to the right at once.</p><h3> Problem C. Stripe<br /></h3><p><u>Brute force</u><br /></p><p>One should keep two sums S1 ans S2, where S1 is the sum of all numbers on the left part of the stripe, and S2 is the sum of the right one. At the beginning S1 = 0 and S2 equals to the sum of all numbers of the stripe. Then we move the border of the parts within a cycle from left to right recalculating the values of S1 and S2 each iteration and increasing the answer when it's necessary.<br /></p><h3>Problem D. Seller Bob<br /></h3><p><u>Greedy, long arithmetics</u><br /></p><p>In this problem we need big integers because the number 2<sup>2000</sup> doesn't fit in int64.<br />We are given an assertion that for every memory stick there will be at most one potential customer. Since 2<sup>xย </sup>> 2<sup>x-1</sup> + 2<sup>x-2</sup> + ... 2<sup>0</sup>, the earnings of selling the most expensive stick will be greater than the earnings of selling all other sticks. So we first try to sell the most expensive stick, then the second one and so on. So one should try to sell sticks in descending order of their costs.<br /></p><h3> Probelm E. Flag 2<br /></h3><p><u>Dynamic programming</u><br /></p><p>In this problem one should use dynamic programming. Consider the function <em>DP(level, A, B)</em> (where <em>A</em> and <em>B</em> are the numbers of colors, from 0 to 25), which returns the minimal number of repaintings required to repaint the first level rows. The last row will be like <em>ABABAB...</em><br /></p><p>Consider recalculating of this function. First, calculate the number of repaintings required for row <em>level</em> to be like <em>ABABAB...</em> (let <em>D</em> will be this number). Obviously, the row can be painted so if the color of the first element of the previous row is not "<em>A</em>" and the second one - not "<em>B</em>" (it's a condition of adjacent cells not to have the same color) or it should be the first row. So <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25, i != j, i != B, j != A.</em><br /><br />Estimate the run time of our program: <em>O(N*26*26*(M+26*26))</em>, this value is smaller than <em>4*10<sup>8</sup></em><br /></p><p><em><sup><br /></sup></em></p><p><strong>Great t</strong><strong>hanks to <a href=\"https://codeforces.com/profile/OBepkJIokEP\">Ilya Akolzin</a> for his help in ย translation</strong><em><sup><br /></sup></em></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/18\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 18 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-201-463\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"201\",\n blogEntryId: \"463\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2318\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #18</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+34</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/ArtDitel\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/ArtDitel\">\n ArtDitel\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/463#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/463#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"473\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (17)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6681\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 00:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6681\" href=\"?#comment-6681\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6681\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6681\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In problem B you can also make the first <span class=\"tex-span\"><i>m</i></span> steps, and if after them the grasshopper didn't fall, it means that he'll fall only after all <span class=\"tex-span\"><i>n</i></span> platforms</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6681 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6681 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6681\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6704\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wbdyni344\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1732/avatar/b910042564e945ad.jpg'/> </a>\n <div><a href=\"/profile/wbdyni344\" title=\"Expert wbdyni344\" class=\"rated-user user-blue\">wbdyni344</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6704\" href=\"?#comment-6704\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6704\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6704\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Solution of problem E is not fast enough to pass it .I've tried to solve it by this alg. but still got TLE.<br />Anyone has a faster alg ?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6704 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6704 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6704\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6705\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:56\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6705\" href=\"?#comment-6705\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6705\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6705\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">It was mentioned that it passes in C++, but not Java.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6705 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6705 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6705\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6710\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6710\" href=\"?#comment-6710\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6710\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6710\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you use Java for this problem, "dumb" solution (with constraint 26^4 for DP step) will get TLE. I wrote more complicated solution, where we count minimal value of recolorings in previous line, with which we can go to specified coloring of current line). This way we can get smaller constraint, cause we can sort values, and check only two of them.</p><p>If you want, you can check my solution (submission 70276), where I've implemented this algorithm.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6710 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6710 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6710\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6721\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:53\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6721\" href=\"?#comment-6721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Actually, dumb solution passes with pretty easy optimisation for java - for each step we will count number of recolorings needed for given color to be on odd position and same for even. This leads O(nm * 26^2 + n * 26^4) "dumb" solution to be O(nm * 26 + n * 26^4) which passes. See my solution for implimentation</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6721\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6751\" commentParentId=\"6721\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:11\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6751\" href=\"?#comment-6751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6721\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I have solution with this asymptotic, and it got TL. Unfortynately, I haven't find your solution, maybe something wrong with my eyes =)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6752\" commentParentId=\"6751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6752\" href=\"?#comment-6752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/contest/18/status/E?order=BY_ARRIVED_ASC\">Here it is</a>ย (5th row)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6764\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/giongto35\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/giongto35\" title=\"Candidate Master giongto35\" class=\"rated-user user-violet\">giongto35</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 09:01\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6764\" href=\"?#comment-6764\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6764\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1772\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6764\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">why so complex?<br />I solved it easily . I save position had minimum value in previous step , it's POS1 , POS2 , DP[level,POS1,POS2] is minimum . In the next step , <em>DP(level, A, B) = </em><em>DP(level-1, POS1, POS2) + D if (POS1<>A) and (POS2 <> B) <br /></em>Else <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25,</em></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6764 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6764 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6764\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6833\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 19:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6833\" href=\"?#comment-6833\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6833\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6833\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I determine all possible checkerings of the the the previous row, and then sort them by non-decreasing cost. Then, for every checkering in the next row, just find the one with lowest cost that is compatible from the row above. This ends up being about O(n^2 log n) where n is ~650 = 26*25. This is less than 4,000,000.<br /><br />After doing a few rounds of this competition though, I'm tired of solutions working in C and not Java :( Slower languages should be given more time (even like, 25% more, though it should probably be closer to 50%), or the time limit should just be larger. The ACM-ICPC does this.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6833 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6833 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6833\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6708\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MciprianM\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3547/avatar/2e9cc229295dcb51.jpg'/> </a>\n <div><a href=\"/profile/MciprianM\" title=\"Expert MciprianM\" class=\"rated-user user-blue\">MciprianM</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 14:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6708\" href=\"?#comment-6708\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6708\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3547\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6708\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you help me with WA on test 25 problem D?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6708 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6708 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6708\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6714\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/fobnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3058/avatar/7723159acb0bf919.jpg'/> </a>\n <div><a href=\"/profile/fobnn\" title=\"Expert fobnn\" class=\"rated-user user-blue\">fobnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 16:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6714\" href=\"?#comment-6714\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6714\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3058\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6714\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">think you!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6714 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6714 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6714\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6722\" commentParentId=\"6714\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6722\" href=\"?#comment-6722\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6714\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6722\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6722\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">That reminds me of:<div>-SOS! We are sinking!</div><div>-What are you thinking about?</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6722 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6722 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6722\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6956\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 09:44\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6956\" href=\"?#comment-6956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D: problem statement says that<br />"A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. " <br />I am unable to understand this.. suppose for example<br /><pre>5<br />win 10<br />win 5<br />sell 5<br />win 1<br />sell 10</pre>in this bob should sell 2^5 to 1st customer because he have memory of that size..<br />orย he will not sell to that customer and keep 2^10 memory to sell 2nd customer.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6966\" commentParentId=\"6956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 10:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6966\" href=\"?#comment-6966\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6966\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6966\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">He sold 2^5 to the 1st customer, but now he wants to know what was the optimal way to sell memory sticks, and for that he should have kept 2^10.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6966 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6966 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6966\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6976\" commentParentId=\"6966\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6976\" href=\"?#comment-6976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6966\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thank you for explaining ....<br />i completely misunderstood during contest...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 23:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7034\" href=\"?#comment-7034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />Is there any way to know the input because i have got WA so many times...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7107\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2010 21:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7107\" href=\"?#comment-7107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7107\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />someone please look at my code (71593 ) and tell me error i have tried lot to find out.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Stripe"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Stripe</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob took a paper stripe of <span class=\"tex-span\"><i>n</i></span> squares (the height of the stripe is 1 square). In each square he wrote an integer number, possibly negative. He became interested in how many ways exist to cut this stripe into two pieces so that the sum of numbers from one piece is equal to the sum of numbers from the other piece, and each piece contains positive integer amount of squares. Would you help Bob solve this problem?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ amount of squares in the stripe. The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated numbers โ they are the numbers written in the squares of the stripe. These numbers are integer and do not exceed 10000 in absolute value.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the amount of ways to cut the stripe into two non-empty pieces so that the sum of numbers from one piece is equal to the sum of numbers from the other piece. Don't forget that it's allowed to cut the stripe along the squares' borders only.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>9<br/>1 5 -6 7 9 -16 0 -2 2<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>1 1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>0 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"79c5a28556c90c3909fbb6d5cf292cd7\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"8911200f14aef28f115e91000f02f60f9dc6c961\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_0a66faf43dfe3579af4332d55ffb18376adbeb63\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Stripe</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob took a paper stripe of <span class=\"tex-span\"><i>n</i></span> squares (the height of the stripe is 1 square). In each square he wrote an integer number, possibly negative. He became interested in how many ways exist to cut this stripe into two pieces so that the sum of numbers from one piece is equal to the sum of numbers from the other piece, and each piece contains positive integer amount of squares. Would you help Bob solve this problem?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ amount of squares in the stripe. The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated numbers โ they are the numbers written in the squares of the stripe. These numbers are integer and do not exceed 10000 in absolute value.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the amount of ways to cut the stripe into two non-empty pieces so that the sum of numbers from one piece is equal to the sum of numbers from the other piece. Don't forget that it's allowed to cut the stripe along the squares' borders only.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>9<br />1 5 -6 7 9 -16 0 -2 2<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />1 1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />0 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" 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class=\"rated-user user-violet\">ArtDitel</a>,\r\n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/462\">Contest discussion</a></p><h3>Problem ะ. Triangle</h3><p><u>Pythagorean theorem, brute force</u></p><p>In this problem you should implement a function, which takes three points and checks whether they form a right-angled triangle. There are a lot of ways to do so, but the simplest one is using a Pythagorean theorem.</p><p> </p><p>You should use squared distances instead of taking roots to overcome problems related to precision errors.</p><p>To examine a triangle on almost-rightness, you can try to move each point in each of four possible directions and check the new triangle using our function. It's good and easy to use two arrays: dx={-1,0,1,0} and dy={0,1,0,-1} for moving. Then we can get the new coordinates of shifted point simply using the following code:<br /></p><blockquote>for (int i = 0; i < 4; i ++)</blockquote><blockquote>{</blockquote><blockquote><blockquote>int x = dx[i] + px;</blockquote></blockquote><blockquote><blockquote>int y = dy[i] + py;</blockquote></blockquote><blockquote><p>}</p></blockquote><h3>Problem B. Platforms</h3><p><u>Simulation</u></p><p>Illustrative picture:</p><p><img src=\"https://s40.radikal.ru/i089/1006/10/c50af7e13d4d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>In this problem you were to determine a coordinate where the grasshoper would fall down. To do so, let's keep the position of grasshoper at a certain moment of time.<br />To avoid TLE one should "move" the grasshoper along a platform in <em>O(1)</em> time (not in the cycle). The grasshoper will do <em>j = (right<sub>i</sub>-x)/d</em> jumps along platform "<em>i</em>", where <em>x</em> is the grasshoper's coordinate (he's standing at the platform), and <em>right<sub>i</sub></em> is a right coordinate of the platform. So we can move the grasshoper on <em>j*d</em> to the right at once.</p><h3> Problem C. Stripe<br /></h3><p><u>Brute force</u><br /></p><p>One should keep two sums S1 ans S2, where S1 is the sum of all numbers on the left part of the stripe, and S2 is the sum of the right one. At the beginning S1 = 0 and S2 equals to the sum of all numbers of the stripe. Then we move the border of the parts within a cycle from left to right recalculating the values of S1 and S2 each iteration and increasing the answer when it's necessary.<br /></p><h3>Problem D. Seller Bob<br /></h3><p><u>Greedy, long arithmetics</u><br /></p><p>In this problem we need big integers because the number 2<sup>2000</sup> doesn't fit in int64.<br />We are given an assertion that for every memory stick there will be at most one potential customer. Since 2<sup>xย </sup>> 2<sup>x-1</sup> + 2<sup>x-2</sup> + ... 2<sup>0</sup>, the earnings of selling the most expensive stick will be greater than the earnings of selling all other sticks. So we first try to sell the most expensive stick, then the second one and so on. So one should try to sell sticks in descending order of their costs.<br /></p><h3> Probelm E. Flag 2<br /></h3><p><u>Dynamic programming</u><br /></p><p>In this problem one should use dynamic programming. Consider the function <em>DP(level, A, B)</em> (where <em>A</em> and <em>B</em> are the numbers of colors, from 0 to 25), which returns the minimal number of repaintings required to repaint the first level rows. The last row will be like <em>ABABAB...</em><br /></p><p>Consider recalculating of this function. First, calculate the number of repaintings required for row <em>level</em> to be like <em>ABABAB...</em> (let <em>D</em> will be this number). Obviously, the row can be painted so if the color of the first element of the previous row is not "<em>A</em>" and the second one - not "<em>B</em>" (it's a condition of adjacent cells not to have the same color) or it should be the first row. So <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25, i != j, i != B, j != A.</em><br /><br />Estimate the run time of our program: <em>O(N*26*26*(M+26*26))</em>, this value is smaller than <em>4*10<sup>8</sup></em><br /></p><p><em><sup><br /></sup></em></p><p><strong>Great t</strong><strong>hanks to <a href=\"https://codeforces.com/profile/OBepkJIokEP\">Ilya Akolzin</a> for his help in ย translation</strong><em><sup><br /></sup></em></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/18\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 18 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-201-463\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"201\",\n blogEntryId: \"463\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2318\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #18</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+34</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/ArtDitel\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/ArtDitel\">\n ArtDitel\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/463#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/463#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"473\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (17)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6681\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 00:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6681\" href=\"?#comment-6681\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6681\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6681\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In problem B you can also make the first <span class=\"tex-span\"><i>m</i></span> steps, and if after them the grasshopper didn't fall, it means that he'll fall only after all <span class=\"tex-span\"><i>n</i></span> platforms</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6681 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6681 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6681\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6704\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wbdyni344\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1732/avatar/b910042564e945ad.jpg'/> </a>\n <div><a href=\"/profile/wbdyni344\" title=\"Expert wbdyni344\" class=\"rated-user user-blue\">wbdyni344</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6704\" href=\"?#comment-6704\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6704\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6704\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Solution of problem E is not fast enough to pass it .I've tried to solve it by this alg. but still got TLE.<br />Anyone has a faster alg ?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6704 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6704 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6704\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6705\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:56\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6705\" href=\"?#comment-6705\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6705\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6705\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">It was mentioned that it passes in C++, but not Java.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6705 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6705 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6705\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6710\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6710\" href=\"?#comment-6710\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6710\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6710\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you use Java for this problem, "dumb" solution (with constraint 26^4 for DP step) will get TLE. I wrote more complicated solution, where we count minimal value of recolorings in previous line, with which we can go to specified coloring of current line). This way we can get smaller constraint, cause we can sort values, and check only two of them.</p><p>If you want, you can check my solution (submission 70276), where I've implemented this algorithm.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6710 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6710 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6710\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6721\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:53\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6721\" href=\"?#comment-6721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Actually, dumb solution passes with pretty easy optimisation for java - for each step we will count number of recolorings needed for given color to be on odd position and same for even. This leads O(nm * 26^2 + n * 26^4) "dumb" solution to be O(nm * 26 + n * 26^4) which passes. See my solution for implimentation</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6721\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6751\" commentParentId=\"6721\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:11\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6751\" href=\"?#comment-6751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6721\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I have solution with this asymptotic, and it got TL. Unfortynately, I haven't find your solution, maybe something wrong with my eyes =)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6752\" commentParentId=\"6751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6752\" href=\"?#comment-6752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/contest/18/status/E?order=BY_ARRIVED_ASC\">Here it is</a>ย (5th row)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6764\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/giongto35\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/giongto35\" title=\"Candidate Master giongto35\" class=\"rated-user user-violet\">giongto35</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 09:01\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6764\" href=\"?#comment-6764\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6764\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1772\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6764\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">why so complex?<br />I solved it easily . I save position had minimum value in previous step , it's POS1 , POS2 , DP[level,POS1,POS2] is minimum . In the next step , <em>DP(level, A, B) = </em><em>DP(level-1, POS1, POS2) + D if (POS1<>A) and (POS2 <> B) <br /></em>Else <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25,</em></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6764 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6764 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6764\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6833\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 19:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6833\" href=\"?#comment-6833\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6833\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6833\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I determine all possible checkerings of the the the previous row, and then sort them by non-decreasing cost. Then, for every checkering in the next row, just find the one with lowest cost that is compatible from the row above. This ends up being about O(n^2 log n) where n is ~650 = 26*25. This is less than 4,000,000.<br /><br />After doing a few rounds of this competition though, I'm tired of solutions working in C and not Java :( Slower languages should be given more time (even like, 25% more, though it should probably be closer to 50%), or the time limit should just be larger. The ACM-ICPC does this.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6833 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6833 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6833\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6708\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MciprianM\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3547/avatar/2e9cc229295dcb51.jpg'/> </a>\n <div><a href=\"/profile/MciprianM\" title=\"Expert MciprianM\" class=\"rated-user user-blue\">MciprianM</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 14:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6708\" href=\"?#comment-6708\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6708\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3547\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6708\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you help me with WA on test 25 problem D?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6708 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6708 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6708\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6714\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/fobnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3058/avatar/7723159acb0bf919.jpg'/> </a>\n <div><a href=\"/profile/fobnn\" title=\"Expert fobnn\" class=\"rated-user user-blue\">fobnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 16:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6714\" href=\"?#comment-6714\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6714\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3058\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6714\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">think you!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6714 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6714 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6714\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6722\" commentParentId=\"6714\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6722\" href=\"?#comment-6722\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6714\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6722\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6722\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">That reminds me of:<div>-SOS! We are sinking!</div><div>-What are you thinking about?</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6722 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6722 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6722\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6956\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 09:44\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6956\" href=\"?#comment-6956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D: problem statement says that<br />"A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. " <br />I am unable to understand this.. suppose for example<br /><pre>5<br />win 10<br />win 5<br />sell 5<br />win 1<br />sell 10</pre>in this bob should sell 2^5 to 1st customer because he have memory of that size..<br />orย he will not sell to that customer and keep 2^10 memory to sell 2nd customer.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6966\" commentParentId=\"6956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 10:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6966\" href=\"?#comment-6966\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6966\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6966\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">He sold 2^5 to the 1st customer, but now he wants to know what was the optimal way to sell memory sticks, and for that he should have kept 2^10.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6966 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6966 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6966\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6976\" commentParentId=\"6966\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6976\" href=\"?#comment-6976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6966\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thank you for explaining ....<br />i completely misunderstood during contest...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 23:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7034\" href=\"?#comment-7034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />Is there any way to know the input because i have got WA so many times...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7107\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2010 21:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7107\" href=\"?#comment-7107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7107\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />someone please look at my code (71593 ) and tell me error i have tried lot to find out.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Seller Bob"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Seller Bob</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Last year Bob earned by selling memory sticks. During each of <span class=\"tex-span\"><i>n</i></span> days of his work one of the two following events took place: </p><ul> <li> A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. </li><li> Bob won some programming competition and got a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick as a prize. Bob could choose whether to present this memory stick to one of his friends, or keep it. </li></ul><p>Bob never kept more than one memory stick, as he feared to mix up their capacities, and deceive a customer unintentionally. It is also known that for each memory stick capacity there was at most one customer, who wanted to buy that memory stick. Now, knowing all the customers' demands and all the prizes won at programming competitions during the last <span class=\"tex-span\"><i>n</i></span> days, Bob wants to know, how much money he could have earned, if he had acted optimally.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ5000</span>) โ amount of Bob's working days. The following <span class=\"tex-span\"><i>n</i></span> lines contain the description of the days. Line <span class=\"tex-font-style-tt\">sell x</span> stands for a day when a customer came to Bob to buy a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick (<span class=\"tex-span\">0โโคโ<i>x</i>โโคโ2000</span>). It's guaranteed that for each <span class=\"tex-span\"><i>x</i></span> there is not more than one line <span class=\"tex-font-style-tt\">sell x</span>. Line <span class=\"tex-font-style-tt\">win x</span> stands for a day when Bob won a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick (<span class=\"tex-span\">0โโคโ<i>x</i>โโคโ2000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the maximum possible earnings for Bob in berllars, that he would have had if he had known all the events beforehand. Don't forget, please, that Bob can't keep more than one memory stick at a time.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>7<br/>win 10<br/>win 5<br/>win 3<br/>sell 5<br/>sell 3<br/>win 10<br/>sell 10<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1056<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>win 5<br/>sell 6<br/>sell 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"582bdd04ae1da93f6044e1fc34e1b16b\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"8911200f14aef28f115e91000f02f60f9dc6c961\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_48b7f98f7b87f9c006cdb655fc041884bcc3c635\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Seller Bob</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Last year Bob earned by selling memory sticks. During each of <span class=\"tex-span\"><i>n</i></span> days of his work one of the two following events took place: </p><ul> <li> A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. </li><li> Bob won some programming competition and got a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick as a prize. Bob could choose whether to present this memory stick to one of his friends, or keep it. </li></ul><p>Bob never kept more than one memory stick, as he feared to mix up their capacities, and deceive a customer unintentionally. It is also known that for each memory stick capacity there was at most one customer, who wanted to buy that memory stick. Now, knowing all the customers' demands and all the prizes won at programming competitions during the last <span class=\"tex-span\"><i>n</i></span> days, Bob wants to know, how much money he could have earned, if he had acted optimally.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ5000</span>) โ amount of Bob's working days. The following <span class=\"tex-span\"><i>n</i></span> lines contain the description of the days. Line <span class=\"tex-font-style-tt\">sell x</span> stands for a day when a customer came to Bob to buy a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick (<span class=\"tex-span\">0โโคโ<i>x</i>โโคโ2000</span>). It's guaranteed that for each <span class=\"tex-span\"><i>x</i></span> there is not more than one line <span class=\"tex-font-style-tt\">sell x</span>. Line <span class=\"tex-font-style-tt\">win x</span> stands for a day when Bob won a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick (<span class=\"tex-span\">0โโคโ<i>x</i>โโคโ2000</span>).</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the maximum possible earnings for Bob in berllars, that he would have had if he had known all the events beforehand. Don't forget, please, that Bob can't keep more than one memory stick at a time.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>7<br />win 10<br />win 5<br />win 3<br />sell 5<br />sell 3<br />win 10<br />sell 10<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1056<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />win 5<br />sell 6<br />sell 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:26</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" 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class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='f8524db49153144b45c3d5e056bc183c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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class=\"rated-user user-violet\">ArtDitel</a>,\r\n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/462\">Contest discussion</a></p><h3>Problem ะ. Triangle</h3><p><u>Pythagorean theorem, brute force</u></p><p>In this problem you should implement a function, which takes three points and checks whether they form a right-angled triangle. There are a lot of ways to do so, but the simplest one is using a Pythagorean theorem.</p><p> </p><p>You should use squared distances instead of taking roots to overcome problems related to precision errors.</p><p>To examine a triangle on almost-rightness, you can try to move each point in each of four possible directions and check the new triangle using our function. It's good and easy to use two arrays: dx={-1,0,1,0} and dy={0,1,0,-1} for moving. Then we can get the new coordinates of shifted point simply using the following code:<br /></p><blockquote>for (int i = 0; i < 4; i ++)</blockquote><blockquote>{</blockquote><blockquote><blockquote>int x = dx[i] + px;</blockquote></blockquote><blockquote><blockquote>int y = dy[i] + py;</blockquote></blockquote><blockquote><p>}</p></blockquote><h3>Problem B. Platforms</h3><p><u>Simulation</u></p><p>Illustrative picture:</p><p><img src=\"https://s40.radikal.ru/i089/1006/10/c50af7e13d4d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>In this problem you were to determine a coordinate where the grasshoper would fall down. To do so, let's keep the position of grasshoper at a certain moment of time.<br />To avoid TLE one should "move" the grasshoper along a platform in <em>O(1)</em> time (not in the cycle). The grasshoper will do <em>j = (right<sub>i</sub>-x)/d</em> jumps along platform "<em>i</em>", where <em>x</em> is the grasshoper's coordinate (he's standing at the platform), and <em>right<sub>i</sub></em> is a right coordinate of the platform. So we can move the grasshoper on <em>j*d</em> to the right at once.</p><h3> Problem C. Stripe<br /></h3><p><u>Brute force</u><br /></p><p>One should keep two sums S1 ans S2, where S1 is the sum of all numbers on the left part of the stripe, and S2 is the sum of the right one. At the beginning S1 = 0 and S2 equals to the sum of all numbers of the stripe. Then we move the border of the parts within a cycle from left to right recalculating the values of S1 and S2 each iteration and increasing the answer when it's necessary.<br /></p><h3>Problem D. Seller Bob<br /></h3><p><u>Greedy, long arithmetics</u><br /></p><p>In this problem we need big integers because the number 2<sup>2000</sup> doesn't fit in int64.<br />We are given an assertion that for every memory stick there will be at most one potential customer. Since 2<sup>xย </sup>> 2<sup>x-1</sup> + 2<sup>x-2</sup> + ... 2<sup>0</sup>, the earnings of selling the most expensive stick will be greater than the earnings of selling all other sticks. So we first try to sell the most expensive stick, then the second one and so on. So one should try to sell sticks in descending order of their costs.<br /></p><h3> Probelm E. Flag 2<br /></h3><p><u>Dynamic programming</u><br /></p><p>In this problem one should use dynamic programming. Consider the function <em>DP(level, A, B)</em> (where <em>A</em> and <em>B</em> are the numbers of colors, from 0 to 25), which returns the minimal number of repaintings required to repaint the first level rows. The last row will be like <em>ABABAB...</em><br /></p><p>Consider recalculating of this function. First, calculate the number of repaintings required for row <em>level</em> to be like <em>ABABAB...</em> (let <em>D</em> will be this number). Obviously, the row can be painted so if the color of the first element of the previous row is not "<em>A</em>" and the second one - not "<em>B</em>" (it's a condition of adjacent cells not to have the same color) or it should be the first row. So <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25, i != j, i != B, j != A.</em><br /><br />Estimate the run time of our program: <em>O(N*26*26*(M+26*26))</em>, this value is smaller than <em>4*10<sup>8</sup></em><br /></p><p><em><sup><br /></sup></em></p><p><strong>Great t</strong><strong>hanks to <a href=\"https://codeforces.com/profile/OBepkJIokEP\">Ilya Akolzin</a> for his help in ย translation</strong><em><sup><br /></sup></em></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/18\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 18 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-201-463\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"201\",\n blogEntryId: \"463\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2318\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #18</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+34</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/ArtDitel\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/ArtDitel\">\n ArtDitel\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/463#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/463#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"473\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (17)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6681\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 00:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6681\" href=\"?#comment-6681\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6681\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6681\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In problem B you can also make the first <span class=\"tex-span\"><i>m</i></span> steps, and if after them the grasshopper didn't fall, it means that he'll fall only after all <span class=\"tex-span\"><i>n</i></span> platforms</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6681 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6681 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6681\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6704\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wbdyni344\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1732/avatar/b910042564e945ad.jpg'/> </a>\n <div><a href=\"/profile/wbdyni344\" title=\"Expert wbdyni344\" class=\"rated-user user-blue\">wbdyni344</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6704\" href=\"?#comment-6704\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6704\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6704\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Solution of problem E is not fast enough to pass it .I've tried to solve it by this alg. but still got TLE.<br />Anyone has a faster alg ?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6704 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6704 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6704\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6705\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:56\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6705\" href=\"?#comment-6705\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6705\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6705\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">It was mentioned that it passes in C++, but not Java.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6705 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6705 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6705\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6710\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6710\" href=\"?#comment-6710\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6710\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6710\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you use Java for this problem, "dumb" solution (with constraint 26^4 for DP step) will get TLE. I wrote more complicated solution, where we count minimal value of recolorings in previous line, with which we can go to specified coloring of current line). This way we can get smaller constraint, cause we can sort values, and check only two of them.</p><p>If you want, you can check my solution (submission 70276), where I've implemented this algorithm.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6710 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6710 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6710\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6721\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:53\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6721\" href=\"?#comment-6721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Actually, dumb solution passes with pretty easy optimisation for java - for each step we will count number of recolorings needed for given color to be on odd position and same for even. This leads O(nm * 26^2 + n * 26^4) "dumb" solution to be O(nm * 26 + n * 26^4) which passes. See my solution for implimentation</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6721\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6751\" commentParentId=\"6721\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:11\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6751\" href=\"?#comment-6751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6721\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I have solution with this asymptotic, and it got TL. Unfortynately, I haven't find your solution, maybe something wrong with my eyes =)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6752\" commentParentId=\"6751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6752\" href=\"?#comment-6752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/contest/18/status/E?order=BY_ARRIVED_ASC\">Here it is</a>ย (5th row)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6764\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/giongto35\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/giongto35\" title=\"Candidate Master giongto35\" class=\"rated-user user-violet\">giongto35</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 09:01\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6764\" href=\"?#comment-6764\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6764\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1772\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6764\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">why so complex?<br />I solved it easily . I save position had minimum value in previous step , it's POS1 , POS2 , DP[level,POS1,POS2] is minimum . In the next step , <em>DP(level, A, B) = </em><em>DP(level-1, POS1, POS2) + D if (POS1<>A) and (POS2 <> B) <br /></em>Else <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25,</em></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6764 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6764 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6764\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6833\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 19:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6833\" href=\"?#comment-6833\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6833\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6833\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I determine all possible checkerings of the the the previous row, and then sort them by non-decreasing cost. Then, for every checkering in the next row, just find the one with lowest cost that is compatible from the row above. This ends up being about O(n^2 log n) where n is ~650 = 26*25. This is less than 4,000,000.<br /><br />After doing a few rounds of this competition though, I'm tired of solutions working in C and not Java :( Slower languages should be given more time (even like, 25% more, though it should probably be closer to 50%), or the time limit should just be larger. The ACM-ICPC does this.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6833 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6833 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6833\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6708\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MciprianM\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3547/avatar/2e9cc229295dcb51.jpg'/> </a>\n <div><a href=\"/profile/MciprianM\" title=\"Expert MciprianM\" class=\"rated-user user-blue\">MciprianM</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 14:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6708\" href=\"?#comment-6708\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6708\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3547\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6708\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you help me with WA on test 25 problem D?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6708 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6708 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6708\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6714\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/fobnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3058/avatar/7723159acb0bf919.jpg'/> </a>\n <div><a href=\"/profile/fobnn\" title=\"Expert fobnn\" class=\"rated-user user-blue\">fobnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 16:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6714\" href=\"?#comment-6714\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6714\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3058\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6714\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">think you!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6714 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6714 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6714\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6722\" commentParentId=\"6714\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6722\" href=\"?#comment-6722\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6714\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6722\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6722\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">That reminds me of:<div>-SOS! We are sinking!</div><div>-What are you thinking about?</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6722 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6722 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6722\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6956\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 09:44\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6956\" href=\"?#comment-6956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D: problem statement says that<br />"A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. " <br />I am unable to understand this.. suppose for example<br /><pre>5<br />win 10<br />win 5<br />sell 5<br />win 1<br />sell 10</pre>in this bob should sell 2^5 to 1st customer because he have memory of that size..<br />orย he will not sell to that customer and keep 2^10 memory to sell 2nd customer.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6966\" commentParentId=\"6956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 10:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6966\" href=\"?#comment-6966\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6966\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6966\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">He sold 2^5 to the 1st customer, but now he wants to know what was the optimal way to sell memory sticks, and for that he should have kept 2^10.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6966 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6966 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6966\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6976\" commentParentId=\"6966\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6976\" href=\"?#comment-6976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6966\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thank you for explaining ....<br />i completely misunderstood during contest...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 23:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7034\" href=\"?#comment-7034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />Is there any way to know the input because i have got WA so many times...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7107\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2010 21:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7107\" href=\"?#comment-7107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7107\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />someone please look at my code (71593 ) and tell me error i have tried lot to find out.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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Flag 2"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Flag 2</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>According to a new ISO standard, a flag of every country should have, strangely enough, a chequered field <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, each square should be wholly painted one of 26 colours. The following restrictions are set: </p><ul> <li> In each row at most two different colours can be used. </li><li> No two adjacent squares can be painted the same colour. </li></ul><p>Pay attention, please, that in one column more than two different colours can be used.</p><p>Berland's government took a decision to introduce changes into their country's flag in accordance with the new standard, at the same time they want these changes to be minimal. By the given description of Berland's flag you should find out the minimum amount of squares that need to be painted different colour to make the flag meet the new ISO standard. You are as well to build one of the possible variants of the new Berland's flag.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 2 integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>m</i>โโคโ500</span>) โ amount of rows and columns in Berland's flag respectively. Then there follows the flag's description: each of the following <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>m</i></span> characters. Each character is a letter from <span class=\"tex-font-style-tt\">a</span> to <span class=\"tex-font-style-tt\">z</span>, and it stands for the colour of the corresponding square.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output the minimum amount of squares that need to be repainted to make the flag meet the new ISO standard. The following <span class=\"tex-span\"><i>n</i></span> lines should contain one of the possible variants of the new flag. Don't forget that the variant of the flag, proposed by you, should be derived from the old flag with the minimum amount of repainted squares. If the answer isn't unique, output any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br/>aaaa<br/>bbbb<br/>cccc<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br/>abab<br/>baba<br/>acac<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>aba<br/>aba<br/>zzz<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/>aba<br/>bab<br/>zbz<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"5693d9de35d869c4c3625e96ff3bc8f2\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"8911200f14aef28f115e91000f02f60f9dc6c961\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"header\"><div class=\"title\">E. Flag 2</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>128 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>According to a new ISO standard, a flag of every country should have, strangely enough, a chequered field <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span>, each square should be wholly painted one of 26 colours. The following restrictions are set: </p><ul> <li> In each row at most two different colours can be used. </li><li> No two adjacent squares can be painted the same colour. </li></ul><p>Pay attention, please, that in one column more than two different colours can be used.</p><p>Berland's government took a decision to introduce changes into their country's flag in accordance with the new standard, at the same time they want these changes to be minimal. By the given description of Berland's flag you should find out the minimum amount of squares that need to be painted different colour to make the flag meet the new ISO standard. You are as well to build one of the possible variants of the new Berland's flag.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 2 integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>m</i>โโคโ500</span>) โ amount of rows and columns in Berland's flag respectively. Then there follows the flag's description: each of the following <span class=\"tex-span\"><i>n</i></span> lines contains <span class=\"tex-span\"><i>m</i></span> characters. Each character is a letter from <span class=\"tex-font-style-tt\">a</span> to <span class=\"tex-font-style-tt\">z</span>, and it stands for the colour of the corresponding square.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output the minimum amount of squares that need to be repainted to make the flag meet the new ISO standard. The following <span class=\"tex-span\"><i>n</i></span> lines should contain one of the possible variants of the new flag. Don't forget that the variant of the flag, proposed by you, should be derived from the old flag with the minimum amount of repainted squares. If the answer isn't unique, output any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 4<br />aaaa<br />bbbb<br />cccc<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>6<br />abab<br />baba<br />acac<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />aba<br />aba<br />zzz<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br />aba<br />bab<br />zbz<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:26</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" 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class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='f8524db49153144b45c3d5e056bc183c'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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class=\"rated-user user-violet\">ArtDitel</a>,\r\n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"https://codeforces.com/blog/entry/462\">Contest discussion</a></p><h3>Problem ะ. Triangle</h3><p><u>Pythagorean theorem, brute force</u></p><p>In this problem you should implement a function, which takes three points and checks whether they form a right-angled triangle. There are a lot of ways to do so, but the simplest one is using a Pythagorean theorem.</p><p> </p><p>You should use squared distances instead of taking roots to overcome problems related to precision errors.</p><p>To examine a triangle on almost-rightness, you can try to move each point in each of four possible directions and check the new triangle using our function. It's good and easy to use two arrays: dx={-1,0,1,0} and dy={0,1,0,-1} for moving. Then we can get the new coordinates of shifted point simply using the following code:<br /></p><blockquote>for (int i = 0; i < 4; i ++)</blockquote><blockquote>{</blockquote><blockquote><blockquote>int x = dx[i] + px;</blockquote></blockquote><blockquote><blockquote>int y = dy[i] + py;</blockquote></blockquote><blockquote><p>}</p></blockquote><h3>Problem B. Platforms</h3><p><u>Simulation</u></p><p>Illustrative picture:</p><p><img src=\"https://s40.radikal.ru/i089/1006/10/c50af7e13d4d.png\" style=\"max-width: 100.0%;max-height: 100.0%;\" /></p><p>In this problem you were to determine a coordinate where the grasshoper would fall down. To do so, let's keep the position of grasshoper at a certain moment of time.<br />To avoid TLE one should "move" the grasshoper along a platform in <em>O(1)</em> time (not in the cycle). The grasshoper will do <em>j = (right<sub>i</sub>-x)/d</em> jumps along platform "<em>i</em>", where <em>x</em> is the grasshoper's coordinate (he's standing at the platform), and <em>right<sub>i</sub></em> is a right coordinate of the platform. So we can move the grasshoper on <em>j*d</em> to the right at once.</p><h3> Problem C. Stripe<br /></h3><p><u>Brute force</u><br /></p><p>One should keep two sums S1 ans S2, where S1 is the sum of all numbers on the left part of the stripe, and S2 is the sum of the right one. At the beginning S1 = 0 and S2 equals to the sum of all numbers of the stripe. Then we move the border of the parts within a cycle from left to right recalculating the values of S1 and S2 each iteration and increasing the answer when it's necessary.<br /></p><h3>Problem D. Seller Bob<br /></h3><p><u>Greedy, long arithmetics</u><br /></p><p>In this problem we need big integers because the number 2<sup>2000</sup> doesn't fit in int64.<br />We are given an assertion that for every memory stick there will be at most one potential customer. Since 2<sup>xย </sup>> 2<sup>x-1</sup> + 2<sup>x-2</sup> + ... 2<sup>0</sup>, the earnings of selling the most expensive stick will be greater than the earnings of selling all other sticks. So we first try to sell the most expensive stick, then the second one and so on. So one should try to sell sticks in descending order of their costs.<br /></p><h3> Probelm E. Flag 2<br /></h3><p><u>Dynamic programming</u><br /></p><p>In this problem one should use dynamic programming. Consider the function <em>DP(level, A, B)</em> (where <em>A</em> and <em>B</em> are the numbers of colors, from 0 to 25), which returns the minimal number of repaintings required to repaint the first level rows. The last row will be like <em>ABABAB...</em><br /></p><p>Consider recalculating of this function. First, calculate the number of repaintings required for row <em>level</em> to be like <em>ABABAB...</em> (let <em>D</em> will be this number). Obviously, the row can be painted so if the color of the first element of the previous row is not "<em>A</em>" and the second one - not "<em>B</em>" (it's a condition of adjacent cells not to have the same color) or it should be the first row. So <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25, i != j, i != B, j != A.</em><br /><br />Estimate the run time of our program: <em>O(N*26*26*(M+26*26))</em>, this value is smaller than <em>4*10<sup>8</sup></em><br /></p><p><em><sup><br /></sup></em></p><p><strong>Great t</strong><strong>hanks to <a href=\"https://codeforces.com/profile/OBepkJIokEP\">Ilya Akolzin</a> for his help in ย translation</strong><em><sup><br /></sup></em></p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/18\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 18 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-201-463\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"201\",\n blogEntryId: \"463\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2318\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #18</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+34</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-463\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/ArtDitel\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/ArtDitel\">\n ArtDitel\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/16/2010 22:31\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/463#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/463#comments\">\n 23\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"473\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (17)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6681\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 00:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6681\" href=\"?#comment-6681\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6681\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6681\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">In problem B you can also make the first <span class=\"tex-span\"><i>m</i></span> steps, and if after them the grasshopper didn't fall, it means that he'll fall only after all <span class=\"tex-span\"><i>n</i></span> platforms</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6681 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6681 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6681\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6704\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wbdyni344\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1732/avatar/b910042564e945ad.jpg'/> </a>\n <div><a href=\"/profile/wbdyni344\" title=\"Expert wbdyni344\" class=\"rated-user user-blue\">wbdyni344</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6704\" href=\"?#comment-6704\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6704\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1732\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6704\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Solution of problem E is not fast enough to pass it .I've tried to solve it by this alg. but still got TLE.<br />Anyone has a faster alg ?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6704 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6704 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6704\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6705\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 13:56\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6705\" href=\"?#comment-6705\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6705\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6705\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">It was mentioned that it passes in C++, but not Java.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6705 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6705 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6705\">\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6710\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 15:26\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6710\" href=\"?#comment-6710\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6710\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6710\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>If you use Java for this problem, "dumb" solution (with constraint 26^4 for DP step) will get TLE. I wrote more complicated solution, where we count minimal value of recolorings in previous line, with which we can go to specified coloring of current line). This way we can get smaller constraint, cause we can sort values, and check only two of them.</p><p>If you want, you can check my solution (submission 70276), where I've implemented this algorithm.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6710 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6710 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6710\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6721\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:53\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6721\" href=\"?#comment-6721\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6721\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6721\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Actually, dumb solution passes with pretty easy optimisation for java - for each step we will count number of recolorings needed for given color to be on odd position and same for even. This leads O(nm * 26^2 + n * 26^4) "dumb" solution to be O(nm * 26 + n * 26^4) which passes. See my solution for implimentation</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6721 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6721 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6721\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6751\" commentParentId=\"6721\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/OleGG\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3522/avatar/b3d1f200972d7b9e.jpg'/> </a>\n <div><a href=\"/profile/OleGG\" title=\"Expert OleGG\" class=\"rated-user user-blue\">OleGG</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:11\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6751\" href=\"?#comment-6751\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6721\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6751\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3522\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6751\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I have solution with this asymptotic, and it got TL. Unfortynately, I haven't find your solution, maybe something wrong with my eyes =)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6751 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6751 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6751\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6752\" commentParentId=\"6751\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 02:50\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6752\" href=\"?#comment-6752\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6751\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6752\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6752\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><a href=\"https://codeforces.com/contest/18/status/E?order=BY_ARRIVED_ASC\">Here it is</a>ย (5th row)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6752 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6752 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6752\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6764\" commentParentId=\"6710\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/giongto35\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/giongto35\" title=\"Candidate Master giongto35\" class=\"rated-user user-violet\">giongto35</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 09:01\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6764\" href=\"?#comment-6764\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6710\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6764\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1772\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6764\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">why so complex?<br />I solved it easily . I save position had minimum value in previous step , it's POS1 , POS2 , DP[level,POS1,POS2] is minimum . In the next step , <em>DP(level, A, B) = </em><em>DP(level-1, POS1, POS2) + D if (POS1<>A) and (POS2 <> B) <br /></em>Else <em>DP(level, A, B) = min(DP(level-1, i, j)) + D , i = 0..25, j = 0..25,</em></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6764 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6764 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6764\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6833\" commentParentId=\"6704\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/18/2010 19:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6833\" href=\"?#comment-6833\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6704\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6833\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6833\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I determine all possible checkerings of the the the previous row, and then sort them by non-decreasing cost. Then, for every checkering in the next row, just find the one with lowest cost that is compatible from the row above. This ends up being about O(n^2 log n) where n is ~650 = 26*25. This is less than 4,000,000.<br /><br />After doing a few rounds of this competition though, I'm tired of solutions working in C and not Java :( Slower languages should be given more time (even like, 25% more, though it should probably be closer to 50%), or the time limit should just be larger. The ACM-ICPC does this.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6833 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6833 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6833\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6708\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MciprianM\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3547/avatar/2e9cc229295dcb51.jpg'/> </a>\n <div><a href=\"/profile/MciprianM\" title=\"Expert MciprianM\" class=\"rated-user user-blue\">MciprianM</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 14:55\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6708\" href=\"?#comment-6708\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6708\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3547\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6708\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you help me with WA on test 25 problem D?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6708 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6708 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6708\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6714\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/fobnn\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3058/avatar/7723159acb0bf919.jpg'/> </a>\n <div><a href=\"/profile/fobnn\" title=\"Expert fobnn\" class=\"rated-user user-blue\">fobnn</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 16:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6714\" href=\"?#comment-6714\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6714\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3058\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6714\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">think you!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6714 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6714 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6714\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6722\" commentParentId=\"6714\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/17/2010 18:54\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6722\" href=\"?#comment-6722\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6714\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6722\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6722\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">That reminds me of:<div>-SOS! We are sinking!</div><div>-What are you thinking about?</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6722 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6722 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6722\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6956\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 09:44\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6956\" href=\"?#comment-6956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D: problem statement says that<br />"A customer came to Bob and asked to sell him a <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> MB memory stick. If Bob had such a stick, he sold it and got <span class=\"tex-span\">2<sup class=\"upper-index\"><i>x</i></sup></span> berllars. " <br />I am unable to understand this.. suppose for example<br /><pre>5<br />win 10<br />win 5<br />sell 5<br />win 1<br />sell 10</pre>in this bob should sell 2^5 to 1st customer because he have memory of that size..<br />orย he will not sell to that customer and keep 2^10 memory to sell 2nd customer.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6966\" commentParentId=\"6956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/slycelote\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/slycelote\" title=\"Master slycelote\" class=\"rated-user user-orange\">slycelote</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 10:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6966\" href=\"?#comment-6966\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6966\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"703\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6966\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">He sold 2^5 to the 1st customer, but now he wants to know what was the optimal way to sell memory sticks, and for that he should have kept 2^10.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6966 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6966 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6966\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"6976\" commentParentId=\"6966\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 12:23\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-6976\" href=\"?#comment-6976\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-6966\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"6976\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-6976\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">thank you for explaining ....<br />i completely misunderstood during contest...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-6976 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-6976 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-6976\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7034\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/19/2010 23:06\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7034\" href=\"?#comment-7034\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7034\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7034\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />Is there any way to know the input because i have got WA so many times...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7034 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7034 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7034\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7107\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/vish\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/592/avatar/3dc3bccb080d32d8.jpg'/> </a>\n <div><a href=\"/profile/vish\" title=\"Expert vish\" class=\"rated-user user-blue\">vish</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/20/2010 21:33\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7107\" href=\"?#comment-7107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7107\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"592\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Problem D : wrong ansย Help ..<br />someone please look at my code (71593 ) and tell me error i have tried lot to find out.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a 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World Football Cup"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. World Football Cup</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Everyone knows that 2010 FIFA World Cup is being held in South Africa now. By the decision of BFA (Berland's Football Association) next World Cup will be held in Berland. BFA took the decision to change some World Cup regulations:</p><ul> <li> the final tournament features <span class=\"tex-span\"><i>n</i></span> teams (<span class=\"tex-span\"><i>n</i></span> is always even) </li><li> the first <span class=\"tex-span\"><i>n</i>โ/โ2</span> teams (according to the standings) come through to the knockout stage </li><li> the standings are made on the following principle: for a victory a team gets 3 points, for a draw โ 1 point, for a defeat โ 0 points. In the first place, teams are ordered in the standings in decreasing order of their points; in the second place โ in decreasing order of the difference between scored and missed goals; in the third place โ in the decreasing order of scored goals </li><li> it's written in Berland's Constitution that the previous regulation helps to order the teams without ambiguity. </li></ul><p>You are asked to write a program that, by the given list of the competing teams and the results of all the matches, will find the list of teams that managed to get through to the knockout stage.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains the only integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ50</span>) โ amount of the teams, taking part in the final tournament of World Cup. The following <span class=\"tex-span\"><i>n</i></span> lines contain the names of these teams, a name is a string of lower-case and upper-case Latin letters, its length doesn't exceed 30 characters. The following <span class=\"tex-span\"><i>n</i>ยท(<i>n</i>โ-โ1)โ/โ2</span> lines describe the held matches in the format <span class=\"tex-font-style-tt\">name1-name2 num1:num2</span>, where <span class=\"tex-span\"><i>name</i>1</span>, <span class=\"tex-span\"><i>name</i>2</span> โ names of the teams; <span class=\"tex-span\"><i>num</i>1</span>, <span class=\"tex-span\"><i>num</i>2</span> (<span class=\"tex-span\">0โโคโ<i>num</i>1,โ<i>num</i>2โโคโ100</span>) โ amount of the goals, scored by the corresponding teams. Accuracy of the descriptions is guaranteed: there are no two team names coinciding accurate to the letters' case; there is no match, where a team plays with itself; each match is met in the descriptions only once.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>n</i>โ/โ2</span> lines โ names of the teams, which managed to get through to the knockout stage in lexicographical order. Output each name in a separate line. No odd characters (including spaces) are allowed. It's guaranteed that the described regulations help to order the teams without ambiguity.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>A<br/>B<br/>C<br/>D<br/>A-B 1:1<br/>A-C 2:2<br/>A-D 1:0<br/>B-C 1:0<br/>B-D 0:3<br/>C-D 0:3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>A<br/>D<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>a<br/>A<br/>a-A 2:1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>a<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"e0db35c8d3f391d4dc7806d59c702452\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"80c38b45b6a45ea642642e710cb066cb4535c361\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_2848b296e13c0e7868331569ed8249e511de2c5a\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. World Football Cup</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Everyone knows that 2010 FIFA World Cup is being held in South Africa now. By the decision of BFA (Berland's Football Association) next World Cup will be held in Berland. BFA took the decision to change some World Cup regulations:</p><ul> <li> the final tournament features <span class=\"tex-span\"><i>n</i></span> teams (<span class=\"tex-span\"><i>n</i></span> is always even) </li><li> the first <span class=\"tex-span\"><i>n</i>โ/โ2</span> teams (according to the standings) come through to the knockout stage </li><li> the standings are made on the following principle: for a victory a team gets 3 points, for a draw โ 1 point, for a defeat โ 0 points. In the first place, teams are ordered in the standings in decreasing order of their points; in the second place โ in decreasing order of the difference between scored and missed goals; in the third place โ in the decreasing order of scored goals </li><li> it's written in Berland's Constitution that the previous regulation helps to order the teams without ambiguity. </li></ul><p>You are asked to write a program that, by the given list of the competing teams and the results of all the matches, will find the list of teams that managed to get through to the knockout stage.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains the only integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ50</span>) โ amount of the teams, taking part in the final tournament of World Cup. The following <span class=\"tex-span\"><i>n</i></span> lines contain the names of these teams, a name is a string of lower-case and upper-case Latin letters, its length doesn't exceed 30 characters. The following <span class=\"tex-span\"><i>n</i>ยท(<i>n</i>โ-โ1)โ/โ2</span> lines describe the held matches in the format <span class=\"tex-font-style-tt\">name1-name2 num1:num2</span>, where <span class=\"tex-span\"><i>name</i>1</span>, <span class=\"tex-span\"><i>name</i>2</span> โ names of the teams; <span class=\"tex-span\"><i>num</i>1</span>, <span class=\"tex-span\"><i>num</i>2</span> (<span class=\"tex-span\">0โโคโ<i>num</i>1,โ<i>num</i>2โโคโ100</span>) โ amount of the goals, scored by the corresponding teams. Accuracy of the descriptions is guaranteed: there are no two team names coinciding accurate to the letters' case; there is no match, where a team plays with itself; each match is met in the descriptions only once.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output <span class=\"tex-span\"><i>n</i>โ/โ2</span> lines โ names of the teams, which managed to get through to the knockout stage in lexicographical order. Output each name in a separate line. No odd characters (including spaces) are allowed. It's guaranteed that the described regulations help to order the teams without ambiguity.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />A<br />B<br />C<br />D<br />A-B 1:1<br />A-C 2:2<br />A-D 1:0<br />B-C 1:0<br />B-D 0:3<br />C-D 0:3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>A<br />D<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />a<br />A<br />a-A 2:1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>a<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = 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\"0\");\r\n\r\n $(this).parent().find(\"pre\").attr(\"id\", preId);\r\n const $copy = $(\"<div title='Copy' data-clipboard-target='#\" + preId + \"' id='\" + cpyId + \"' class='input-output-copier'>Copy</div>\");\r\n $(this).append($copy);\r\n\r\n const clipboard = new Clipboard('#' + cpyId, {\r\n text: function (trigger) {\r\n const pre = document.querySelector('#' + preId);\r\n const lines = pre.querySelectorAll(\".test-example-line\");\r\n return Codeforces.filterClipboardText(pre.innerText, lines.length);\r\n }\r\n });\r\n\r\n const isInput = $(this).parent().hasClass(\"input\");\r\n\r\n clipboard.on('success', function (e) {\r\n if (isInput) {\r\n Codeforces.showMessage(\"The example input has been copied into the clipboard\");\r\n } else {\r\n Codeforces.showMessage(\"The example output has been copied into the clipboard\");\r\n }\r\n e.clearSelection();\r\n });\r\n });\r\n\r\n $(\".test-form-item input\").change(function () {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:24</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36b8243f0044940680edefae5a855cb6'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 โ Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div 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class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New 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title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/YuukaKazami\">YuukaKazami</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/YuukaKazami\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/YuukaKazami\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/YuukaKazami\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/YuukaKazami\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/YuukaKazami\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/YuukaKazami\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/YuukaKazami\" style=\"text-decoration:none;color:black !important;\">YuukaKazami's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"559\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/559\"> Code Force Beta Round 19 Solution\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a>,\r\n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\"><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 13.5pt;font-family: Simsun , serif;color: black;\">I find that no one write a solution about this contest..So I write one..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">A. World Football Cup</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">I think is' just a problem about writing codeย </span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">quickly and correctly.Just follow the statement.</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if you use c++ STL will make you life easier</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">B. Checkout Assistant</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First,for every i increaseย t<sub>i</sub>ย by 1..then you will</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย see that statement require sum of t of the items<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย bigger or equal to n..and their sum of c shouldย <b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">be minimal..so it's just a 0-1 knapsack problem.<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">C. Deletion of Repeats</span><b><span lang=\"EN-US\" style=\"font-size: 17.0pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First let's generate all repeats.In a repeat,the<br /> ย first number and the middle number must be theย <br /> same, so we just look at all pair of postion whichย <br /> have same number..Thank to the statement..Thereย <br /> are at most O(10N) such pair..And use suffix arrayย <br /> to check if each pair can build a repeat...Thenย <br /> just sort all the interval and go through then toย <br /> get the answer...<br /><a href=\"https://en.wikipedia.org/wiki/Suffix_array\">http://en.wikipedia.org/wiki/Suffix_array</a><br />maybe you think suffix array is hard to code..youย <br />can use hash and binary search to do the same..<br />my code hereย </span><a href=\"http://www.ideone.com/N5zPS\">http://www.ideone.com/N5zPS</a></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">D. Points<br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First of all,do theย discretization.Then the biggestย <br /> value of x is n,so we can build a Segment Tree toย <br /> Ask the question "what is the first place from ย <br /> postion x and its value is bigger than y"..if weย <br /> find such postion we just find the smallest Y-valueย <br /> bigger than y in such postion--it can be done usingย <br /> set's operation upper_bound...<br /><a href=\"https://en.wikipedia.org/wiki/Segment_tree\">http://en.wikipedia.org/wiki/Segment_tree</a><br /> so the algorithm is clear..For every possible valueย <br /> of x use a set to store all y value in it..And everyย <br /> time the action is "find" or "remove" just changeย <br /> this set and update the Segment Tree..otherwise useย <br /> Segment Tree to find the answer..</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"></span><span style=\"font-family: Simsun , serif;font-size: 22.0px;\">my code hereย </span><a href=\"http://www.ideone.com/4iNol\">http://www.ideone.com/4iNol</a></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">E. Fairy</span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Arial , sans-serif;color: black;\"><br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">It's a interesting problem.If you for every edge,ย <br /> try to remove it and check if it is aย bipartiteย <br /> graph..I think it will get TLE..so let'sย analysisย <br /> the property of bipartite graph..<br /><a href=\"https://en.wikipedia.org/wiki/Bipartite_graph\">http://en.wikipedia.org/wiki/Bipartite_graph</a><br />After reading it...we know..<br /> It should never contain a cycle of odd length...<br /> and it can be 2-colored..<br /> so first build aย spanning forest for the graph..<br /> and do the 2-color on it(Tree can be 2-colored).<br /> forย convenience.<br /> Let TreeEdge={all edge in forest}<br /> NotTreeEdge={All edge}/TreeEdge<br /> ErrorEdge={all edge that two endpoint have the same color..}<br /> NotErorEdge=NotTreeEdge/ErroEdge..<br /> First,consider a edge form NotTreeEdge,remove itย <br /> can't change any node's color..so..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if |ErrorEdge|=0 of course we can remove all NotTreeEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if =1 we just can remove the ErrorEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if >1 we can't remove any from NotTreeEdge<br /> Now,Let consider a Edge e from TreeEdge..<br /> Let Path(Edge e)=the path in forest between e's two endpoints..<br /> if there is a Edge e' from ErrorEdge that Path(e')ย <br /> didn't ย go through e..it will destroy the bipartiteย <br /> graph..<br /> if there is a Edge e' from ErrorEdge that Path(e') go through e and there is a Edge e'' from NotErrorEdge that Path(e'') go through e..it will also destroy the bipartite graph..<br /> so now we need to know for every edge,how many such path go through it..it require a data structure...<br /> one way is to use heavy-light decomposition then we can update every path in O(LogN^2)...<br /> another way is to use Link-Cut Tree..It can do the same in O(LogN)....<br />if you didn't see Link-Cut tree before,you can read this</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"><a href=\"https://en.wikipedia.org/wiki/Link/cut_tree\">http://www.cs.cmu.edu/~sleator/papers/dynamic-trees.pdf</a><br />or my code..use heavy-light decompositionย </span><a href=\"http://www.ideone.com/dPS5N\">http://www.ideone.com/dPS5N</a></p></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/19\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 19</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1664-559\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1664\",\n blogEntryId: \"559\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=solution\" class=\"tag notice\" style=\"text-decoration: none;\">solution</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+6</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/YuukaKazami\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/YuukaKazami\">\n YuukaKazami\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/559#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/559#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"569\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8814\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/freopen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/769/avatar/4f63f1bce26e9eaf.jpg'/> </a>\n <div><a href=\"/profile/freopen\" title=\"Master freopen\" class=\"rated-user user-orange\">freopen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8814\" href=\"?#comment-8814\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8814\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"769\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8814\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why sizes of letters are not equal?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8814 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8814 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8814\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8821\" commentParentId=\"8814\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/YuukaKazami\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/582/avatar/ecf2f6ced3d15a2c.jpg'/> </a>\n <div><a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8821\" href=\"?#comment-8821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8814\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"582\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I don't know how to use the editor.. I'm ย trying to make it look nicer:)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8821\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45545\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 09:15\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45545\" href=\"?#comment-45545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Orz...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81107\" commentParentId=\"45545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:06\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81107\" href=\"?#comment-81107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-45545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81107\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does it mean? Is it some Chinese abbreviation?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81107 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81107\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81110\" commentParentId=\"81107\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:14\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81110\" href=\"?#comment-81110\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-81107\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81110\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81110\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found it myself.. "orz, a posture emoticon representing a kneeling, bowing, or comically fallen over person"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81110 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81110 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81110\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 11:11\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45553\" href=\"?#comment-45553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">ym WJMZBMR!!!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45553\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56504\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cherudim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25704/avatar/697bcaedc1a7af08.jpg'/> </a>\n <div><a href=\"/profile/cherudim\" title=\"Master cherudim\" class=\"rated-user user-orange\">cherudim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2011 09:54\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56504\" href=\"?#comment-56504\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56504\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56504\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">lovely english.....</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56504 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56504 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56504\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"820677\" commentParentId=\"56504\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/_CodeInfinity_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/_CodeInfinity_\" title=\"Expert _CodeInfinity_\" class=\"rated-user user-blue\">_CodeInfinity_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/25/2021 15:58\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-820677\" href=\"?#comment-820677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-56504\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"820677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"2011039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-820677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-820677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-820677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-820677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56573\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2011 07:48\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56573\" href=\"?#comment-56573\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56573\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56573\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">As a matter of fact, CF19E does not need a data structure, since we need not update it on-line. We can do it off-line with an easier way.<br />Path u-v can be divided to u-lca and v-lca, so add u, add v, and decrease lca by two. and that works.<br />More easily, we can use dfs-tree, to avoid looking for lca.<br />So the algorithm is O(n + m).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56573 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56573 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56573\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119638\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Faygoat\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Faygoat\" title=\"Unrated, Faygoat\" class=\"rated-user user-black\">Faygoat</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 10:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119638\" href=\"?#comment-119638\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119638\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"80174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119638\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Anyone know if D can be solved using an augmented (self-balancing) binary search tree? To me, it does but I can't get a working solution. Any thoughts?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119638 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119638 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119638\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"590081\" commentParentId=\"119638\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2020 19:22\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-590081\" href=\"?#comment-590081\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119638\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"590081\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-590081\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We don't do that here.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-590081 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-590081 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-590081\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347303\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/04/2017 22:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347303\" href=\"?#comment-347303\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347303\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347303\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the solution!</p><p>In problem C, I think there are N*45 such pairs. // C(10,2)=45 Because you want not only the adjacant pairs. We need no suffix array nor hash. Just brute-force to compare the substrings is enough, thanks to the "no more than 10 times" constraint.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347303 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347303 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347303\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347409\" commentParentId=\"347303\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/05/2017 15:40\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347409\" href=\"?#comment-347409\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347303\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347409\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347409\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry this should be M*45, where M is the number of different letters appeared. So ~ N*4.5 in worst case. Thanks <a class=\"rated-user user-violet\" href=\"/profile/kokosha\" title=\"Candidate Master kokosha\">kokosha</a> for pointing out :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347409 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347409 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347409\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"540078\" commentParentId=\"347409\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2019 21:26\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-540078\" href=\"?#comment-540078\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347409\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"540078\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-540078\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you're wrong here. There will be $$$M*10$$$ pairs. Consider we have $$$3$$$ indices $$$i, j, k$$$ for a character, where $$$i \\le j \\le k$$$. If the pair $$$(i, j)$$$ is a repeat and also $$$(i, k)$$$ is a repeat, then, we don't need to store $$$(i, k)$$$. This is because the pair $$$(i, j)$$$ has a smaller length and will be processed first after which, the substring starting at $$$i$$$ will be deleted. So, $$$(i, k)$$$ will never be processed. So, for every position $$$i$$$, we need only the closest position to the right $$$j$$$, s.t. $$$(i, j)$$$ is a repeat, i.e., substring of length $$$(j-i)$$$ starting at $$$i$$$ = substring of length $$$(j-i)$$$ starting at $$$j$$$. So, there are only $$$M*10 \\sim N$$$ pairs, that we need to store.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-540078 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-540078 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-540078\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"885642\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxylluvio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2152992/avatar/474fbab4d1688cf0.jpg'/> </a>\n <div><a href=\"/profile/lxylluvio\" title=\"Specialist lxylluvio\" class=\"rated-user user-cyan\">lxylluvio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2022 12:21\">20 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-885642\" href=\"?#comment-885642\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"885642\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"2152992\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-885642\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why does my $$$\\tt{Edge}$$$ browser show $$$\\text{404 Not Found}$$$ when I click on the link <code>http://www.ideone.com/dPS5N</code>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-885642 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-885642 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Checkout Assistant"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Checkout Assistant</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob came to a cash & carry store, put <span class=\"tex-span\"><i>n</i></span> items into his trolley, and went to the checkout counter to pay. Each item is described by its price <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> and time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in seconds that a checkout assistant spends on this item. While the checkout assistant is occupied with some item, Bob can steal some other items from his trolley. To steal one item Bob needs exactly 1 second. What is the minimum amount of money that Bob will have to pay to the checkout assistant? Remember, please, that it is Bob, who determines the order of items for the checkout assistant.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2000</span>). In each of the following <span class=\"tex-span\"><i>n</i></span> lines each item is described by a pair of numbers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0โโคโ<i>t</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ2000,โ1โโคโ<i>c</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">9</sup></span>). If <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> is 0, Bob won't be able to steal anything, while the checkout assistant is occupied with item <span class=\"tex-span\"><i>i</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output one number โ answer to the problem: what is the minimum amount of money that Bob will have to pay.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>2 10<br/>0 20<br/>1 5<br/>1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br/>0 1<br/>0 10<br/>0 100<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>111<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"ae2e98834bf528d5c15d2c4f08dc95a1\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"80c38b45b6a45ea642642e710cb066cb4535c361\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Checkout Assistant</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob came to a cash & carry store, put <span class=\"tex-span\"><i>n</i></span> items into his trolley, and went to the checkout counter to pay. Each item is described by its price <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> and time <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> in seconds that a checkout assistant spends on this item. While the checkout assistant is occupied with some item, Bob can steal some other items from his trolley. To steal one item Bob needs exactly 1 second. What is the minimum amount of money that Bob will have to pay to the checkout assistant? Remember, please, that it is Bob, who determines the order of items for the checkout assistant.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2000</span>). In each of the following <span class=\"tex-span\"><i>n</i></span> lines each item is described by a pair of numbers <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>c</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">0โโคโ<i>t</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ2000,โ1โโคโ<i>c</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">9</sup></span>). If <span class=\"tex-span\"><i>t</i><sub class=\"lower-index\"><i>i</i></sub></span> is 0, Bob won't be able to steal anything, while the checkout assistant is occupied with item <span class=\"tex-span\"><i>i</i></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output one number โ answer to the problem: what is the minimum amount of money that Bob will have to pay.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />2 10<br />0 20<br />1 5<br />1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3<br />0 1<br />0 10<br />0 100<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>111<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36b8243f0044940680edefae5a855cb6'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/YuukaKazami\">YuukaKazami</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/YuukaKazami\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/YuukaKazami\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/YuukaKazami\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/YuukaKazami\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/YuukaKazami\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/YuukaKazami\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/YuukaKazami\" style=\"text-decoration:none;color:black !important;\">YuukaKazami's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"559\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/559\"> Code Force Beta Round 19 Solution\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a>,\r\n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\"><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 13.5pt;font-family: Simsun , serif;color: black;\">I find that no one write a solution about this contest..So I write one..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">A. World Football Cup</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">I think is' just a problem about writing codeย </span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">quickly and correctly.Just follow the statement.</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if you use c++ STL will make you life easier</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">B. Checkout Assistant</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First,for every i increaseย t<sub>i</sub>ย by 1..then you will</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย see that statement require sum of t of the items<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย bigger or equal to n..and their sum of c shouldย <b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">be minimal..so it's just a 0-1 knapsack problem.<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">C. Deletion of Repeats</span><b><span lang=\"EN-US\" style=\"font-size: 17.0pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First let's generate all repeats.In a repeat,the<br /> ย first number and the middle number must be theย <br /> same, so we just look at all pair of postion whichย <br /> have same number..Thank to the statement..Thereย <br /> are at most O(10N) such pair..And use suffix arrayย <br /> to check if each pair can build a repeat...Thenย <br /> just sort all the interval and go through then toย <br /> get the answer...<br /><a href=\"https://en.wikipedia.org/wiki/Suffix_array\">http://en.wikipedia.org/wiki/Suffix_array</a><br />maybe you think suffix array is hard to code..youย <br />can use hash and binary search to do the same..<br />my code hereย </span><a href=\"http://www.ideone.com/N5zPS\">http://www.ideone.com/N5zPS</a></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">D. Points<br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First of all,do theย discretization.Then the biggestย <br /> value of x is n,so we can build a Segment Tree toย <br /> Ask the question "what is the first place from ย <br /> postion x and its value is bigger than y"..if weย <br /> find such postion we just find the smallest Y-valueย <br /> bigger than y in such postion--it can be done usingย <br /> set's operation upper_bound...<br /><a href=\"https://en.wikipedia.org/wiki/Segment_tree\">http://en.wikipedia.org/wiki/Segment_tree</a><br /> so the algorithm is clear..For every possible valueย <br /> of x use a set to store all y value in it..And everyย <br /> time the action is "find" or "remove" just changeย <br /> this set and update the Segment Tree..otherwise useย <br /> Segment Tree to find the answer..</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"></span><span style=\"font-family: Simsun , serif;font-size: 22.0px;\">my code hereย </span><a href=\"http://www.ideone.com/4iNol\">http://www.ideone.com/4iNol</a></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">E. Fairy</span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Arial , sans-serif;color: black;\"><br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">It's a interesting problem.If you for every edge,ย <br /> try to remove it and check if it is aย bipartiteย <br /> graph..I think it will get TLE..so let'sย analysisย <br /> the property of bipartite graph..<br /><a href=\"https://en.wikipedia.org/wiki/Bipartite_graph\">http://en.wikipedia.org/wiki/Bipartite_graph</a><br />After reading it...we know..<br /> It should never contain a cycle of odd length...<br /> and it can be 2-colored..<br /> so first build aย spanning forest for the graph..<br /> and do the 2-color on it(Tree can be 2-colored).<br /> forย convenience.<br /> Let TreeEdge={all edge in forest}<br /> NotTreeEdge={All edge}/TreeEdge<br /> ErrorEdge={all edge that two endpoint have the same color..}<br /> NotErorEdge=NotTreeEdge/ErroEdge..<br /> First,consider a edge form NotTreeEdge,remove itย <br /> can't change any node's color..so..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if |ErrorEdge|=0 of course we can remove all NotTreeEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if =1 we just can remove the ErrorEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if >1 we can't remove any from NotTreeEdge<br /> Now,Let consider a Edge e from TreeEdge..<br /> Let Path(Edge e)=the path in forest between e's two endpoints..<br /> if there is a Edge e' from ErrorEdge that Path(e')ย <br /> didn't ย go through e..it will destroy the bipartiteย <br /> graph..<br /> if there is a Edge e' from ErrorEdge that Path(e') go through e and there is a Edge e'' from NotErrorEdge that Path(e'') go through e..it will also destroy the bipartite graph..<br /> so now we need to know for every edge,how many such path go through it..it require a data structure...<br /> one way is to use heavy-light decomposition then we can update every path in O(LogN^2)...<br /> another way is to use Link-Cut Tree..It can do the same in O(LogN)....<br />if you didn't see Link-Cut tree before,you can read this</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"><a href=\"https://en.wikipedia.org/wiki/Link/cut_tree\">http://www.cs.cmu.edu/~sleator/papers/dynamic-trees.pdf</a><br />or my code..use heavy-light decompositionย </span><a href=\"http://www.ideone.com/dPS5N\">http://www.ideone.com/dPS5N</a></p></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/19\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 19</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1664-559\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1664\",\n blogEntryId: \"559\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=solution\" class=\"tag notice\" style=\"text-decoration: none;\">solution</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+6</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/YuukaKazami\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/YuukaKazami\">\n YuukaKazami\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/559#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/559#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"569\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8814\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/freopen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/769/avatar/4f63f1bce26e9eaf.jpg'/> </a>\n <div><a href=\"/profile/freopen\" title=\"Master freopen\" class=\"rated-user user-orange\">freopen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8814\" href=\"?#comment-8814\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8814\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"769\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8814\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why sizes of letters are not equal?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8814 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8814 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8814\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8821\" commentParentId=\"8814\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/YuukaKazami\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/582/avatar/ecf2f6ced3d15a2c.jpg'/> </a>\n <div><a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8821\" href=\"?#comment-8821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8814\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"582\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I don't know how to use the editor.. I'm ย trying to make it look nicer:)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8821\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45545\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 09:15\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45545\" href=\"?#comment-45545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Orz...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81107\" commentParentId=\"45545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:06\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81107\" href=\"?#comment-81107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-45545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81107\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does it mean? Is it some Chinese abbreviation?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81107 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81107\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81110\" commentParentId=\"81107\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:14\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81110\" href=\"?#comment-81110\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-81107\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81110\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81110\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found it myself.. "orz, a posture emoticon representing a kneeling, bowing, or comically fallen over person"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81110 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81110 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81110\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 11:11\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45553\" href=\"?#comment-45553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">ym WJMZBMR!!!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45553\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56504\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cherudim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25704/avatar/697bcaedc1a7af08.jpg'/> </a>\n <div><a href=\"/profile/cherudim\" title=\"Master cherudim\" class=\"rated-user user-orange\">cherudim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2011 09:54\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56504\" href=\"?#comment-56504\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56504\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56504\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">lovely english.....</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56504 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56504 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56504\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"820677\" commentParentId=\"56504\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/_CodeInfinity_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/_CodeInfinity_\" title=\"Expert _CodeInfinity_\" class=\"rated-user user-blue\">_CodeInfinity_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/25/2021 15:58\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-820677\" href=\"?#comment-820677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-56504\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"820677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"2011039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-820677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-820677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-820677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-820677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56573\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2011 07:48\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56573\" href=\"?#comment-56573\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56573\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56573\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">As a matter of fact, CF19E does not need a data structure, since we need not update it on-line. We can do it off-line with an easier way.<br />Path u-v can be divided to u-lca and v-lca, so add u, add v, and decrease lca by two. and that works.<br />More easily, we can use dfs-tree, to avoid looking for lca.<br />So the algorithm is O(n + m).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56573 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56573 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56573\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119638\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Faygoat\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Faygoat\" title=\"Unrated, Faygoat\" class=\"rated-user user-black\">Faygoat</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 10:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119638\" href=\"?#comment-119638\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119638\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"80174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119638\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Anyone know if D can be solved using an augmented (self-balancing) binary search tree? To me, it does but I can't get a working solution. Any thoughts?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119638 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119638 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119638\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"590081\" commentParentId=\"119638\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2020 19:22\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-590081\" href=\"?#comment-590081\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119638\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"590081\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-590081\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We don't do that here.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-590081 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-590081 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-590081\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347303\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/04/2017 22:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347303\" href=\"?#comment-347303\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347303\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347303\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the solution!</p><p>In problem C, I think there are N*45 such pairs. // C(10,2)=45 Because you want not only the adjacant pairs. We need no suffix array nor hash. Just brute-force to compare the substrings is enough, thanks to the "no more than 10 times" constraint.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347303 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347303 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347303\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347409\" commentParentId=\"347303\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/05/2017 15:40\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347409\" href=\"?#comment-347409\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347303\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347409\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347409\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry this should be M*45, where M is the number of different letters appeared. So ~ N*4.5 in worst case. Thanks <a class=\"rated-user user-violet\" href=\"/profile/kokosha\" title=\"Candidate Master kokosha\">kokosha</a> for pointing out :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347409 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347409 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347409\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"540078\" commentParentId=\"347409\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2019 21:26\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-540078\" href=\"?#comment-540078\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347409\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"540078\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-540078\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you're wrong here. There will be $$$M*10$$$ pairs. Consider we have $$$3$$$ indices $$$i, j, k$$$ for a character, where $$$i \\le j \\le k$$$. If the pair $$$(i, j)$$$ is a repeat and also $$$(i, k)$$$ is a repeat, then, we don't need to store $$$(i, k)$$$. This is because the pair $$$(i, j)$$$ has a smaller length and will be processed first after which, the substring starting at $$$i$$$ will be deleted. So, $$$(i, k)$$$ will never be processed. So, for every position $$$i$$$, we need only the closest position to the right $$$j$$$, s.t. $$$(i, j)$$$ is a repeat, i.e., substring of length $$$(j-i)$$$ starting at $$$i$$$ = substring of length $$$(j-i)$$$ starting at $$$j$$$. So, there are only $$$M*10 \\sim N$$$ pairs, that we need to store.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-540078 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-540078 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-540078\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"885642\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxylluvio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2152992/avatar/474fbab4d1688cf0.jpg'/> </a>\n <div><a href=\"/profile/lxylluvio\" title=\"Specialist lxylluvio\" class=\"rated-user user-cyan\">lxylluvio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2022 12:21\">20 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-885642\" href=\"?#comment-885642\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"885642\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"2152992\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-885642\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why does my $$$\\tt{Edge}$$$ browser show $$$\\text{404 Not Found}$$$ when I click on the link <code>http://www.ideone.com/dPS5N</code>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-885642 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-885642 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Deletion of Repeats"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Deletion of Repeats</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob saw a string. It contained so many different letters, that the letters were marked by numbers, but at the same time each letter could be met in the string at most 10 times. Bob didn't like that string, because it contained repeats: a repeat of length <span class=\"tex-span\"><i>x</i></span> is such a substring of length <span class=\"tex-span\">2<i>x</i></span>, that its first half coincides character by character with its second half. Bob started deleting all the repeats from the string. He does it as follows: while it's possible, Bob takes the shortest repeat, if it is not unique, he takes the leftmost one, and deletes its left half and everything that is to the left of this repeat.</p><p>You're given the string seen by Bob. Find out, what it will look like after Bob deletes all the repeats in the way described above.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ length of the string. The following line contains <span class=\"tex-span\"><i>n</i></span> space-separated integer numbers from <span class=\"tex-span\">0</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">9</sup></span> inclusive โ numbers that stand for the letters of the string. It's guaranteed that each letter can be met in the string at most 10 times.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output the length of the string's part, left after Bob's deletions. In the second line output all the letters (separated by a space) of the string, left after Bob deleted all the repeats in the described way.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br/>1 2 3 1 2 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>1 2 3 <br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br/>4 5 6 5 6 7 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>7 <br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"49e88472d2be9fd048091108dd25aa16\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"80c38b45b6a45ea642642e710cb066cb4535c361\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_6561658857c141d33d05f8ca3c9776b7768e8edb\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Deletion of Repeats</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob saw a string. It contained so many different letters, that the letters were marked by numbers, but at the same time each letter could be met in the string at most 10 times. Bob didn't like that string, because it contained repeats: a repeat of length <span class=\"tex-span\"><i>x</i></span> is such a substring of length <span class=\"tex-span\">2<i>x</i></span>, that its first half coincides character by character with its second half. Bob started deleting all the repeats from the string. He does it as follows: while it's possible, Bob takes the shortest repeat, if it is not unique, he takes the leftmost one, and deletes its left half and everything that is to the left of this repeat.</p><p>You're given the string seen by Bob. Find out, what it will look like after Bob deletes all the repeats in the way described above.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ length of the string. The following line contains <span class=\"tex-span\"><i>n</i></span> space-separated integer numbers from <span class=\"tex-span\">0</span> to <span class=\"tex-span\">10<sup class=\"upper-index\">9</sup></span> inclusive โ numbers that stand for the letters of the string. It's guaranteed that each letter can be met in the string at most 10 times.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output the length of the string's part, left after Bob's deletions. In the second line output all the letters (separated by a space) of the string, left after Bob deleted all the repeats in the described way.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>6<br />1 2 3 1 2 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />1 2 3 <br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>7<br />4 5 6 5 6 7 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />7 <br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:24</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36b8243f0044940680edefae5a855cb6'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/YuukaKazami\">YuukaKazami</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/YuukaKazami\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/YuukaKazami\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/YuukaKazami\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/YuukaKazami\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/YuukaKazami\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/YuukaKazami\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/YuukaKazami\" style=\"text-decoration:none;color:black !important;\">YuukaKazami's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"559\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/559\"> Code Force Beta Round 19 Solution\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a>,\r\n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\"><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 13.5pt;font-family: Simsun , serif;color: black;\">I find that no one write a solution about this contest..So I write one..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">A. World Football Cup</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">I think is' just a problem about writing codeย </span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">quickly and correctly.Just follow the statement.</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if you use c++ STL will make you life easier</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">B. Checkout Assistant</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First,for every i increaseย t<sub>i</sub>ย by 1..then you will</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย see that statement require sum of t of the items<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย bigger or equal to n..and their sum of c shouldย <b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">be minimal..so it's just a 0-1 knapsack problem.<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">C. Deletion of Repeats</span><b><span lang=\"EN-US\" style=\"font-size: 17.0pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First let's generate all repeats.In a repeat,the<br /> ย first number and the middle number must be theย <br /> same, so we just look at all pair of postion whichย <br /> have same number..Thank to the statement..Thereย <br /> are at most O(10N) such pair..And use suffix arrayย <br /> to check if each pair can build a repeat...Thenย <br /> just sort all the interval and go through then toย <br /> get the answer...<br /><a href=\"https://en.wikipedia.org/wiki/Suffix_array\">http://en.wikipedia.org/wiki/Suffix_array</a><br />maybe you think suffix array is hard to code..youย <br />can use hash and binary search to do the same..<br />my code hereย </span><a href=\"http://www.ideone.com/N5zPS\">http://www.ideone.com/N5zPS</a></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">D. Points<br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First of all,do theย discretization.Then the biggestย <br /> value of x is n,so we can build a Segment Tree toย <br /> Ask the question "what is the first place from ย <br /> postion x and its value is bigger than y"..if weย <br /> find such postion we just find the smallest Y-valueย <br /> bigger than y in such postion--it can be done usingย <br /> set's operation upper_bound...<br /><a href=\"https://en.wikipedia.org/wiki/Segment_tree\">http://en.wikipedia.org/wiki/Segment_tree</a><br /> so the algorithm is clear..For every possible valueย <br /> of x use a set to store all y value in it..And everyย <br /> time the action is "find" or "remove" just changeย <br /> this set and update the Segment Tree..otherwise useย <br /> Segment Tree to find the answer..</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"></span><span style=\"font-family: Simsun , serif;font-size: 22.0px;\">my code hereย </span><a href=\"http://www.ideone.com/4iNol\">http://www.ideone.com/4iNol</a></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">E. Fairy</span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Arial , sans-serif;color: black;\"><br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">It's a interesting problem.If you for every edge,ย <br /> try to remove it and check if it is aย bipartiteย <br /> graph..I think it will get TLE..so let'sย analysisย <br /> the property of bipartite graph..<br /><a href=\"https://en.wikipedia.org/wiki/Bipartite_graph\">http://en.wikipedia.org/wiki/Bipartite_graph</a><br />After reading it...we know..<br /> It should never contain a cycle of odd length...<br /> and it can be 2-colored..<br /> so first build aย spanning forest for the graph..<br /> and do the 2-color on it(Tree can be 2-colored).<br /> forย convenience.<br /> Let TreeEdge={all edge in forest}<br /> NotTreeEdge={All edge}/TreeEdge<br /> ErrorEdge={all edge that two endpoint have the same color..}<br /> NotErorEdge=NotTreeEdge/ErroEdge..<br /> First,consider a edge form NotTreeEdge,remove itย <br /> can't change any node's color..so..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if |ErrorEdge|=0 of course we can remove all NotTreeEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if =1 we just can remove the ErrorEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if >1 we can't remove any from NotTreeEdge<br /> Now,Let consider a Edge e from TreeEdge..<br /> Let Path(Edge e)=the path in forest between e's two endpoints..<br /> if there is a Edge e' from ErrorEdge that Path(e')ย <br /> didn't ย go through e..it will destroy the bipartiteย <br /> graph..<br /> if there is a Edge e' from ErrorEdge that Path(e') go through e and there is a Edge e'' from NotErrorEdge that Path(e'') go through e..it will also destroy the bipartite graph..<br /> so now we need to know for every edge,how many such path go through it..it require a data structure...<br /> one way is to use heavy-light decomposition then we can update every path in O(LogN^2)...<br /> another way is to use Link-Cut Tree..It can do the same in O(LogN)....<br />if you didn't see Link-Cut tree before,you can read this</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"><a href=\"https://en.wikipedia.org/wiki/Link/cut_tree\">http://www.cs.cmu.edu/~sleator/papers/dynamic-trees.pdf</a><br />or my code..use heavy-light decompositionย </span><a href=\"http://www.ideone.com/dPS5N\">http://www.ideone.com/dPS5N</a></p></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/19\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 19</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1664-559\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1664\",\n blogEntryId: \"559\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=solution\" class=\"tag notice\" style=\"text-decoration: none;\">solution</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+6</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/YuukaKazami\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/YuukaKazami\">\n YuukaKazami\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/559#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/559#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"569\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8814\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/freopen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/769/avatar/4f63f1bce26e9eaf.jpg'/> </a>\n <div><a href=\"/profile/freopen\" title=\"Master freopen\" class=\"rated-user user-orange\">freopen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8814\" href=\"?#comment-8814\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8814\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"769\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8814\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why sizes of letters are not equal?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8814 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8814 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8814\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8821\" commentParentId=\"8814\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/YuukaKazami\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/582/avatar/ecf2f6ced3d15a2c.jpg'/> </a>\n <div><a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8821\" href=\"?#comment-8821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8814\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"582\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I don't know how to use the editor.. I'm ย trying to make it look nicer:)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8821\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45545\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 09:15\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45545\" href=\"?#comment-45545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Orz...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81107\" commentParentId=\"45545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:06\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81107\" href=\"?#comment-81107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-45545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81107\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does it mean? Is it some Chinese abbreviation?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81107 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81107\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81110\" commentParentId=\"81107\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:14\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81110\" href=\"?#comment-81110\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-81107\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81110\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81110\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found it myself.. "orz, a posture emoticon representing a kneeling, bowing, or comically fallen over person"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81110 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81110 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81110\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 11:11\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45553\" href=\"?#comment-45553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">ym WJMZBMR!!!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45553\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56504\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cherudim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25704/avatar/697bcaedc1a7af08.jpg'/> </a>\n <div><a href=\"/profile/cherudim\" title=\"Master cherudim\" class=\"rated-user user-orange\">cherudim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2011 09:54\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56504\" href=\"?#comment-56504\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56504\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56504\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">lovely english.....</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56504 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56504 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56504\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"820677\" commentParentId=\"56504\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/_CodeInfinity_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/_CodeInfinity_\" title=\"Expert _CodeInfinity_\" class=\"rated-user user-blue\">_CodeInfinity_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/25/2021 15:58\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-820677\" href=\"?#comment-820677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-56504\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"820677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"2011039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-820677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-820677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-820677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-820677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56573\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2011 07:48\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56573\" href=\"?#comment-56573\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56573\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56573\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">As a matter of fact, CF19E does not need a data structure, since we need not update it on-line. We can do it off-line with an easier way.<br />Path u-v can be divided to u-lca and v-lca, so add u, add v, and decrease lca by two. and that works.<br />More easily, we can use dfs-tree, to avoid looking for lca.<br />So the algorithm is O(n + m).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56573 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56573 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56573\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119638\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Faygoat\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Faygoat\" title=\"Unrated, Faygoat\" class=\"rated-user user-black\">Faygoat</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 10:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119638\" href=\"?#comment-119638\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119638\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"80174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119638\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Anyone know if D can be solved using an augmented (self-balancing) binary search tree? To me, it does but I can't get a working solution. Any thoughts?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119638 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119638 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119638\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"590081\" commentParentId=\"119638\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2020 19:22\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-590081\" href=\"?#comment-590081\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119638\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"590081\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-590081\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We don't do that here.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-590081 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-590081 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-590081\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347303\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/04/2017 22:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347303\" href=\"?#comment-347303\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347303\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347303\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the solution!</p><p>In problem C, I think there are N*45 such pairs. // C(10,2)=45 Because you want not only the adjacant pairs. We need no suffix array nor hash. Just brute-force to compare the substrings is enough, thanks to the "no more than 10 times" constraint.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347303 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347303 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347303\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347409\" commentParentId=\"347303\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/05/2017 15:40\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347409\" href=\"?#comment-347409\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347303\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347409\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347409\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry this should be M*45, where M is the number of different letters appeared. So ~ N*4.5 in worst case. Thanks <a class=\"rated-user user-violet\" href=\"/profile/kokosha\" title=\"Candidate Master kokosha\">kokosha</a> for pointing out :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347409 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347409 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347409\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"540078\" commentParentId=\"347409\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2019 21:26\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-540078\" href=\"?#comment-540078\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347409\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"540078\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-540078\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you're wrong here. There will be $$$M*10$$$ pairs. Consider we have $$$3$$$ indices $$$i, j, k$$$ for a character, where $$$i \\le j \\le k$$$. If the pair $$$(i, j)$$$ is a repeat and also $$$(i, k)$$$ is a repeat, then, we don't need to store $$$(i, k)$$$. This is because the pair $$$(i, j)$$$ has a smaller length and will be processed first after which, the substring starting at $$$i$$$ will be deleted. So, $$$(i, k)$$$ will never be processed. So, for every position $$$i$$$, we need only the closest position to the right $$$j$$$, s.t. $$$(i, j)$$$ is a repeat, i.e., substring of length $$$(j-i)$$$ starting at $$$i$$$ = substring of length $$$(j-i)$$$ starting at $$$j$$$. So, there are only $$$M*10 \\sim N$$$ pairs, that we need to store.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-540078 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-540078 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-540078\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"885642\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxylluvio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2152992/avatar/474fbab4d1688cf0.jpg'/> </a>\n <div><a href=\"/profile/lxylluvio\" title=\"Specialist lxylluvio\" class=\"rated-user user-cyan\">lxylluvio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2022 12:21\">20 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-885642\" href=\"?#comment-885642\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"885642\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"2152992\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-885642\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why does my $$$\\tt{Edge}$$$ browser show $$$\\text{404 Not Found}$$$ when I click on the link <code>http://www.ideone.com/dPS5N</code>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-885642 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-885642 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Points"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Pete and Bob invented a new interesting game. Bob takes a sheet of paper and locates a Cartesian coordinate system on it as follows: point <span class=\"tex-span\">(0,โ0)</span> is located in the bottom-left corner, <span class=\"tex-span\"><i>Ox</i></span> axis is directed right, <span class=\"tex-span\"><i>Oy</i></span> axis is directed up. Pete gives Bob requests of three types: </p><ul> <li> <span class=\"tex-font-style-tt\">add x y</span> โ on the sheet of paper Bob marks a point with coordinates <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. For each request of this type it's guaranteed that point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span> is not yet marked on Bob's sheet at the time of the request. </li><li> <span class=\"tex-font-style-tt\">remove x y</span> โ on the sheet of paper Bob erases the previously marked point with coordinates <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. For each request of this type it's guaranteed that point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span> is already marked on Bob's sheet at the time of the request. </li><li> <span class=\"tex-font-style-tt\">find x y</span> โ on the sheet of paper Bob finds all the marked points, lying strictly above and strictly to the right of point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. Among these points Bob chooses the leftmost one, if it is not unique, he chooses the bottommost one, and gives its coordinates to Pete. </li></ul><p>Bob managed to answer the requests, when they were 10, 100 or 1000, but when their amount grew up to <span class=\"tex-span\">2ยท10<sup class=\"upper-index\">5</sup></span>, Bob failed to cope. Now he needs a program that will answer all Pete's requests. Help Bob, please!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2ยท10<sup class=\"upper-index\">5</sup></span>) โ amount of requests. Then there follow <span class=\"tex-span\"><i>n</i></span> lines โ descriptions of the requests. <span class=\"tex-font-style-tt\">add x y</span> describes the request to add a point, <span class=\"tex-font-style-tt\">remove x y</span> โ the request to erase a point, <span class=\"tex-font-style-tt\">find x y</span> โ the request to find the bottom-left point. All the coordinates in the input file are non-negative and don't exceed <span class=\"tex-span\">10<sup class=\"upper-index\">9</sup></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each request of type <span class=\"tex-font-style-tt\">find x y</span> output in a separate line the answer to it โ coordinates of the bottommost among the leftmost marked points, lying strictly above and to the right of point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. If there are no points strictly above and to the right of point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>, output <span class=\"tex-font-style-tt\">-1</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>7<br/>add 1 1<br/>add 3 4<br/>find 0 0<br/>remove 1 1<br/>find 0 0<br/>add 1 1<br/>find 0 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 1<br/>3 4<br/>1 1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>13<br/>add 5 5<br/>add 5 6<br/>add 5 7<br/>add 6 5<br/>add 6 6<br/>add 6 7<br/>add 7 5<br/>add 7 6<br/>add 7 7<br/>find 6 6<br/>remove 7 7<br/>find 6 6<br/>find 4 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7 7<br/>-1<br/>5 5<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"a052c9fdd9ccb59f6eb4e5b0eb22e346\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"80c38b45b6a45ea642642e710cb066cb4535c361\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/19\">Codeforces Beta Round 19</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Heaps, binary search trees, segment trees, hash tables, etc\">\r\n data structures\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='a052c9fdd9ccb59f6eb4e5b0eb22e346'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"93\"/>\r\n 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class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/484\" title=\"Codeforces Beta Round #19\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"104:105\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/559\" title=\"Code Force Beta Round 19 Solution\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"106\" resourceName=\"Code Force Beta Round 19 Solution\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: 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if (!pre) {\r\n s = s.replace(/\\s+/g, \" \");\r\n }\r\n if (s.length > 0) {\r\n result.push(s);\r\n }\r\n }\r\n\r\n if (pre && node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_826e05ecdc78ef4eb4b566c6890870dbe4d2b33f\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Points</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Pete and Bob invented a new interesting game. Bob takes a sheet of paper and locates a Cartesian coordinate system on it as follows: point <span class=\"tex-span\">(0,โ0)</span> is located in the bottom-left corner, <span class=\"tex-span\"><i>Ox</i></span> axis is directed right, <span class=\"tex-span\"><i>Oy</i></span> axis is directed up. Pete gives Bob requests of three types: </p><ul> <li> <span class=\"tex-font-style-tt\">add x y</span> โ on the sheet of paper Bob marks a point with coordinates <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. For each request of this type it's guaranteed that point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span> is not yet marked on Bob's sheet at the time of the request. </li><li> <span class=\"tex-font-style-tt\">remove x y</span> โ on the sheet of paper Bob erases the previously marked point with coordinates <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. For each request of this type it's guaranteed that point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span> is already marked on Bob's sheet at the time of the request. </li><li> <span class=\"tex-font-style-tt\">find x y</span> โ on the sheet of paper Bob finds all the marked points, lying strictly above and strictly to the right of point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. Among these points Bob chooses the leftmost one, if it is not unique, he chooses the bottommost one, and gives its coordinates to Pete. </li></ul><p>Bob managed to answer the requests, when they were 10, 100 or 1000, but when their amount grew up to <span class=\"tex-span\">2ยท10<sup class=\"upper-index\">5</sup></span>, Bob failed to cope. Now he needs a program that will answer all Pete's requests. Help Bob, please!</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ2ยท10<sup class=\"upper-index\">5</sup></span>) โ amount of requests. Then there follow <span class=\"tex-span\"><i>n</i></span> lines โ descriptions of the requests. <span class=\"tex-font-style-tt\">add x y</span> describes the request to add a point, <span class=\"tex-font-style-tt\">remove x y</span> โ the request to erase a point, <span class=\"tex-font-style-tt\">find x y</span> โ the request to find the bottom-left point. All the coordinates in the input file are non-negative and don't exceed <span class=\"tex-span\">10<sup class=\"upper-index\">9</sup></span>.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>For each request of type <span class=\"tex-font-style-tt\">find x y</span> output in a separate line the answer to it โ coordinates of the bottommost among the leftmost marked points, lying strictly above and to the right of point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>. If there are no points strictly above and to the right of point <span class=\"tex-span\">(<i>x</i>,โ<i>y</i>)</span>, output <span class=\"tex-font-style-tt\">-1</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>7<br />add 1 1<br />add 3 4<br />find 0 0<br />remove 1 1<br />find 0 0<br />add 1 1<br />find 0 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 1<br />3 4<br />1 1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>13<br />add 5 5<br />add 5 6<br />add 5 7<br />add 6 5<br />add 6 6<br />add 6 7<br />add 7 5<br />add 7 6<br />add 7 7<br />find 6 6<br />remove 7 7<br />find 6 6<br />find 4 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>7 7<br />-1<br />5 5<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36b8243f0044940680edefae5a855cb6'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/119880\">It's Happening! Meta Hacker Cup 2023 Schedule</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/DaviddeGea1\" title=\"Expert DaviddeGea1\" class=\"rated-user user-blue\">DaviddeGea1</a> →\r\n <a href=\"/blog/entry/70917\">Number of ways of dividing an array into 2 parts such that sum of each part is > k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bekh\" title=\"Master Bekh\" class=\"rated-user user-orange\">Bekh</a> →\r\n <a href=\"/blog/entry/74245\">Questions and doubts regarding Aliens DP trick</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/cgy4ever\" title=\"International Grandmaster cgy4ever\" class=\"rated-user user-red\">cgy4ever</a> →\r\n <a href=\"/blog/entry/8192\">Codeforces Round #190 โ Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/hocky\" title=\"Candidate Master hocky\" class=\"rated-user user-violet\">hocky</a> →\r\n <a href=\"/blog/entry/95323\">FBHC wuining uw Day? Incwease uw stacc size! (ใ
ยด ห `)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/liouzhou_101\" title=\"International Master liouzhou_101\" class=\"rated-user user-orange\">liouzhou_101</a> →\r\n <a href=\"/blog/entry/87598\">Editorial of Codeforces Round #700</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/yeon_gist\" title=\"Newbie yeon_gist\" class=\"rated-user user-gray\">yeon_gist</a> →\r\n <a href=\"/blog/entry/121170\">plusMinusPermutation computing error</a>\r\n <img alt=\"Text created or updated\" title=\"Text created or updated\" src=\"//codeforces.org/s/81027/images/icons/x-update-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/altforminuscontribution\" title=\"Newbie altforminuscontribution\" class=\"rated-user user-gray\">altforminuscontribution</a> →\r\n <a href=\"/blog/entry/121162\">My screen get unexpectedly big, what should I do</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/atcoder_official\" title=\"Unrated, atcoder_official\" class=\"rated-user user-black\">atcoder_official</a> →\r\n <a href=\"/blog/entry/121120\">We will hold UNIQUE VISION Programming Contest 2023 Autumn(AtCoder Beginner Contest 323)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/YouStill_DontKnowMeYet\" title=\"Candidate Master YouStill_DontKnowMeYet\" class=\"rated-user user-violet\">YouStill_DontKnowMeYet</a> →\r\n <a href=\"/blog/entry/117659\">[GYM] Al-Baath Collegiate Programming Contest 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/ankancool\" title=\"Expert ankancool\" class=\"rated-user user-blue\">ankancool</a> →\r\n <a href=\"/blog/entry/121136\">Invitation to AstroByte 2023</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/GeZhiyuan\" title=\"Grandmaster GeZhiyuan\" class=\"rated-user user-red\">GeZhiyuan</a> →\r\n <a href=\"/blog/entry/120943\">Codeforces Round 901 (Div. 1, Div. 2) Editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a> →\r\n <a href=\"/blog/entry/120772\">PSA: Increase your stack size before the Meta Hacker Cup, here's how</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/dino_merlin\" title=\"Expert dino_merlin\" class=\"rated-user user-blue\">dino_merlin</a> →\r\n <a href=\"/blog/entry/121145\">Intuitive approach for CEOI Kangaroo?</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/icecuber\" title=\"Grandmaster icecuber\" class=\"rated-user user-red\">icecuber</a> →\r\n <a href=\"/blog/entry/70018\">CSES DP section editorial</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Bn00b\" title=\"Newbie Bn00b\" class=\"rated-user user-gray\">Bn00b</a> →\r\n <a href=\"/blog/entry/98820\">[FEATURE REQUEST : ATCODER] TOPICS TAGS AND SORTING BY SOLVE COUNT</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n <img alt=\"Necropost\" title=\"Necropost\" src=\"//codeforces.org/s/81027/images/icons/hourglass.png\" style=\"vertical-align:middle; position: relative; top: 1px;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a> →\r\n <a href=\"/blog/entry/121163\">AtCoder Regular Contest 166 Announcement</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/windva\" title=\"Grandmaster windva\" class=\"rated-user user-red\">windva</a> →\r\n <a href=\"/blog/entry/120644\">Codeforces Round 899 (Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Misa-Misa\" title=\"Expert Misa-Misa\" class=\"rated-user user-blue\">Misa-Misa</a> →\r\n <a href=\"/blog/entry/121157\">Someone please help me understand this.</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/shivam565\" title=\"Specialist shivam565\" class=\"rated-user user-cyan\">shivam565</a> →\r\n <a href=\"/blog/entry/108348\">Total number of subarrays with sum atmost k</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n </ul>\r\n </div>\r\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/recent-actions\">Detailed →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n</div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li><a\r\n href=\"/profile/YuukaKazami\">YuukaKazami</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/YuukaKazami\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/YuukaKazami\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/YuukaKazami\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/YuukaKazami\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/YuukaKazami\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/YuukaKazami\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/YuukaKazami\" style=\"text-decoration:none;color:black !important;\">YuukaKazami's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"559\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/559\"> Code Force Beta Round 19 Solution\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a>,\r\n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\"><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 13.5pt;font-family: Simsun , serif;color: black;\">I find that no one write a solution about this contest..So I write one..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">A. World Football Cup</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">I think is' just a problem about writing codeย </span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">quickly and correctly.Just follow the statement.</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if you use c++ STL will make you life easier</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">B. Checkout Assistant</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First,for every i increaseย t<sub>i</sub>ย by 1..then you will</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย see that statement require sum of t of the items<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย bigger or equal to n..and their sum of c shouldย <b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">be minimal..so it's just a 0-1 knapsack problem.<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">C. Deletion of Repeats</span><b><span lang=\"EN-US\" style=\"font-size: 17.0pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First let's generate all repeats.In a repeat,the<br /> ย first number and the middle number must be theย <br /> same, so we just look at all pair of postion whichย <br /> have same number..Thank to the statement..Thereย <br /> are at most O(10N) such pair..And use suffix arrayย <br /> to check if each pair can build a repeat...Thenย <br /> just sort all the interval and go through then toย <br /> get the answer...<br /><a href=\"https://en.wikipedia.org/wiki/Suffix_array\">http://en.wikipedia.org/wiki/Suffix_array</a><br />maybe you think suffix array is hard to code..youย <br />can use hash and binary search to do the same..<br />my code hereย </span><a href=\"http://www.ideone.com/N5zPS\">http://www.ideone.com/N5zPS</a></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">D. Points<br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First of all,do theย discretization.Then the biggestย <br /> value of x is n,so we can build a Segment Tree toย <br /> Ask the question "what is the first place from ย <br /> postion x and its value is bigger than y"..if weย <br /> find such postion we just find the smallest Y-valueย <br /> bigger than y in such postion--it can be done usingย <br /> set's operation upper_bound...<br /><a href=\"https://en.wikipedia.org/wiki/Segment_tree\">http://en.wikipedia.org/wiki/Segment_tree</a><br /> so the algorithm is clear..For every possible valueย <br /> of x use a set to store all y value in it..And everyย <br /> time the action is "find" or "remove" just changeย <br /> this set and update the Segment Tree..otherwise useย <br /> Segment Tree to find the answer..</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"></span><span style=\"font-family: Simsun , serif;font-size: 22.0px;\">my code hereย </span><a href=\"http://www.ideone.com/4iNol\">http://www.ideone.com/4iNol</a></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">E. Fairy</span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Arial , sans-serif;color: black;\"><br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">It's a interesting problem.If you for every edge,ย <br /> try to remove it and check if it is aย bipartiteย <br /> graph..I think it will get TLE..so let'sย analysisย <br /> the property of bipartite graph..<br /><a href=\"https://en.wikipedia.org/wiki/Bipartite_graph\">http://en.wikipedia.org/wiki/Bipartite_graph</a><br />After reading it...we know..<br /> It should never contain a cycle of odd length...<br /> and it can be 2-colored..<br /> so first build aย spanning forest for the graph..<br /> and do the 2-color on it(Tree can be 2-colored).<br /> forย convenience.<br /> Let TreeEdge={all edge in forest}<br /> NotTreeEdge={All edge}/TreeEdge<br /> ErrorEdge={all edge that two endpoint have the same color..}<br /> NotErorEdge=NotTreeEdge/ErroEdge..<br /> First,consider a edge form NotTreeEdge,remove itย <br /> can't change any node's color..so..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if |ErrorEdge|=0 of course we can remove all NotTreeEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if =1 we just can remove the ErrorEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if >1 we can't remove any from NotTreeEdge<br /> Now,Let consider a Edge e from TreeEdge..<br /> Let Path(Edge e)=the path in forest between e's two endpoints..<br /> if there is a Edge e' from ErrorEdge that Path(e')ย <br /> didn't ย go through e..it will destroy the bipartiteย <br /> graph..<br /> if there is a Edge e' from ErrorEdge that Path(e') go through e and there is a Edge e'' from NotErrorEdge that Path(e'') go through e..it will also destroy the bipartite graph..<br /> so now we need to know for every edge,how many such path go through it..it require a data structure...<br /> one way is to use heavy-light decomposition then we can update every path in O(LogN^2)...<br /> another way is to use Link-Cut Tree..It can do the same in O(LogN)....<br />if you didn't see Link-Cut tree before,you can read this</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"><a href=\"https://en.wikipedia.org/wiki/Link/cut_tree\">http://www.cs.cmu.edu/~sleator/papers/dynamic-trees.pdf</a><br />or my code..use heavy-light decompositionย </span><a href=\"http://www.ideone.com/dPS5N\">http://www.ideone.com/dPS5N</a></p></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/19\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 19</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1664-559\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1664\",\n blogEntryId: \"559\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=solution\" class=\"tag notice\" style=\"text-decoration: none;\">solution</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+6</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/YuukaKazami\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/YuukaKazami\">\n YuukaKazami\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/559#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/559#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"569\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8814\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/freopen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/769/avatar/4f63f1bce26e9eaf.jpg'/> </a>\n <div><a href=\"/profile/freopen\" title=\"Master freopen\" class=\"rated-user user-orange\">freopen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8814\" href=\"?#comment-8814\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8814\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"769\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8814\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why sizes of letters are not equal?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8814 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8814 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8814\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8821\" commentParentId=\"8814\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/YuukaKazami\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/582/avatar/ecf2f6ced3d15a2c.jpg'/> </a>\n <div><a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8821\" href=\"?#comment-8821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8814\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"582\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I don't know how to use the editor.. I'm ย trying to make it look nicer:)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8821\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45545\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 09:15\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45545\" href=\"?#comment-45545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Orz...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81107\" commentParentId=\"45545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:06\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81107\" href=\"?#comment-81107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-45545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81107\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does it mean? Is it some Chinese abbreviation?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81107 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81107\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81110\" commentParentId=\"81107\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:14\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81110\" href=\"?#comment-81110\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-81107\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81110\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81110\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found it myself.. "orz, a posture emoticon representing a kneeling, bowing, or comically fallen over person"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81110 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81110 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81110\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 11:11\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45553\" href=\"?#comment-45553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">ym WJMZBMR!!!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45553\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56504\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cherudim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25704/avatar/697bcaedc1a7af08.jpg'/> </a>\n <div><a href=\"/profile/cherudim\" title=\"Master cherudim\" class=\"rated-user user-orange\">cherudim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2011 09:54\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56504\" href=\"?#comment-56504\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56504\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56504\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">lovely english.....</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56504 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56504 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56504\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"820677\" commentParentId=\"56504\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/_CodeInfinity_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/_CodeInfinity_\" title=\"Expert _CodeInfinity_\" class=\"rated-user user-blue\">_CodeInfinity_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/25/2021 15:58\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-820677\" href=\"?#comment-820677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-56504\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"820677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"2011039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-820677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-820677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-820677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-820677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56573\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2011 07:48\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56573\" href=\"?#comment-56573\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56573\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56573\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">As a matter of fact, CF19E does not need a data structure, since we need not update it on-line. We can do it off-line with an easier way.<br />Path u-v can be divided to u-lca and v-lca, so add u, add v, and decrease lca by two. and that works.<br />More easily, we can use dfs-tree, to avoid looking for lca.<br />So the algorithm is O(n + m).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56573 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56573 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56573\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119638\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Faygoat\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Faygoat\" title=\"Unrated, Faygoat\" class=\"rated-user user-black\">Faygoat</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 10:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119638\" href=\"?#comment-119638\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119638\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"80174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119638\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Anyone know if D can be solved using an augmented (self-balancing) binary search tree? To me, it does but I can't get a working solution. Any thoughts?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119638 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119638 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119638\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"590081\" commentParentId=\"119638\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2020 19:22\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-590081\" href=\"?#comment-590081\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119638\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"590081\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-590081\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We don't do that here.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-590081 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-590081 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-590081\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347303\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/04/2017 22:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347303\" href=\"?#comment-347303\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347303\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347303\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the solution!</p><p>In problem C, I think there are N*45 such pairs. // C(10,2)=45 Because you want not only the adjacant pairs. We need no suffix array nor hash. Just brute-force to compare the substrings is enough, thanks to the "no more than 10 times" constraint.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347303 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347303 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347303\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347409\" commentParentId=\"347303\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/05/2017 15:40\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347409\" href=\"?#comment-347409\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347303\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347409\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347409\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry this should be M*45, where M is the number of different letters appeared. So ~ N*4.5 in worst case. Thanks <a class=\"rated-user user-violet\" href=\"/profile/kokosha\" title=\"Candidate Master kokosha\">kokosha</a> for pointing out :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347409 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347409 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347409\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"540078\" commentParentId=\"347409\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2019 21:26\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-540078\" href=\"?#comment-540078\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347409\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"540078\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-540078\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you're wrong here. There will be $$$M*10$$$ pairs. Consider we have $$$3$$$ indices $$$i, j, k$$$ for a character, where $$$i \\le j \\le k$$$. If the pair $$$(i, j)$$$ is a repeat and also $$$(i, k)$$$ is a repeat, then, we don't need to store $$$(i, k)$$$. This is because the pair $$$(i, j)$$$ has a smaller length and will be processed first after which, the substring starting at $$$i$$$ will be deleted. So, $$$(i, k)$$$ will never be processed. So, for every position $$$i$$$, we need only the closest position to the right $$$j$$$, s.t. $$$(i, j)$$$ is a repeat, i.e., substring of length $$$(j-i)$$$ starting at $$$i$$$ = substring of length $$$(j-i)$$$ starting at $$$j$$$. So, there are only $$$M*10 \\sim N$$$ pairs, that we need to store.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-540078 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-540078 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-540078\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"885642\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxylluvio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2152992/avatar/474fbab4d1688cf0.jpg'/> </a>\n <div><a href=\"/profile/lxylluvio\" title=\"Specialist lxylluvio\" class=\"rated-user user-cyan\">lxylluvio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2022 12:21\">20 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-885642\" href=\"?#comment-885642\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"885642\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"2152992\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-885642\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why does my $$$\\tt{Edge}$$$ browser show $$$\\text{404 Not Found}$$$ when I click on the link <code>http://www.ideone.com/dPS5N</code>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-885642 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-885642 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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Fairy"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fairy</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1.5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once upon a time there lived a good fairy A. One day a fine young man B came to her and asked to predict his future. The fairy looked into her magic ball and said that soon the fine young man will meet the most beautiful princess ever and will marry her. Then she drew on a sheet of paper <span class=\"tex-span\"><i>n</i></span> points and joined some of them with segments, each of the segments starts in some point and ends in some other point. Having drawn that picture, she asked the young man to erase one of the segments from the sheet. Then she tries to colour each point red or blue so, that there is no segment having points of the same colour as its ends. If she manages to do so, the prediction will come true. B wants to meet the most beautiful princess, that's why he asks you to help him. Find all the segments that will help him to meet the princess.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains two integer numbers: <span class=\"tex-span\"><i>n</i></span> โ amount of the drawn points and <span class=\"tex-span\"><i>m</i></span> โ amount of the drawn segments (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">4</sup>,โ0โโคโ<i>m</i>โโคโ10<sup class=\"upper-index\">4</sup></span>). The following <span class=\"tex-span\"><i>m</i></span> lines contain the descriptions of the segments. Each description contains two different space-separated integer numbers <span class=\"tex-span\"><i>v</i></span>, <span class=\"tex-span\"><i>u</i></span> (<span class=\"tex-span\">1โโคโ<i>v</i>โโคโ<i>n</i>,โ1โโคโ<i>u</i>โโคโ<i>n</i></span>) โ indexes of the points, joined by this segment. No segment is met in the description twice.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output number <span class=\"tex-span\"><i>k</i></span> โ amount of the segments in the answer. In the second line output <span class=\"tex-span\"><i>k</i></span> space-separated numbers โ indexes of these segments in ascending order. Each index should be output only once. Segments are numbered from 1 in the input order.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 4<br/>1 2<br/>1 3<br/>2 4<br/>3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br/>1 2 3 4 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br/>1 2<br/>2 3<br/>3 4<br/>4 1<br/>1 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>5 </pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"25e78214d2b357b5d8fe6a0922bb10db\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - E - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"80c38b45b6a45ea642642e710cb066cb4535c361\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - E - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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href=\"/blog/entry/559\" title=\"Code Force Beta Round 19 Solution\" target=\"_blank\">Tutorial <span class=\"resource-locale\">(en)</span></a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"106\" resourceName=\"Code Force Beta Round 19 Solution\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/19\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/19/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/19/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/19/status\">Status</a></li>\r\n <li><a\r\n 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class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"E\" data-uuid=\"ps_5ecd80e5cd58363d877faf648202cffba692ef2f\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">E. Fairy</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1.5 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once upon a time there lived a good fairy A. One day a fine young man B came to her and asked to predict his future. The fairy looked into her magic ball and said that soon the fine young man will meet the most beautiful princess ever and will marry her. Then she drew on a sheet of paper <span class=\"tex-span\"><i>n</i></span> points and joined some of them with segments, each of the segments starts in some point and ends in some other point. Having drawn that picture, she asked the young man to erase one of the segments from the sheet. Then she tries to colour each point red or blue so, that there is no segment having points of the same colour as its ends. If she manages to do so, the prediction will come true. B wants to meet the most beautiful princess, that's why he asks you to help him. Find all the segments that will help him to meet the princess.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains two integer numbers: <span class=\"tex-span\"><i>n</i></span> โ amount of the drawn points and <span class=\"tex-span\"><i>m</i></span> โ amount of the drawn segments (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">4</sup>,โ0โโคโ<i>m</i>โโคโ10<sup class=\"upper-index\">4</sup></span>). The following <span class=\"tex-span\"><i>m</i></span> lines contain the descriptions of the segments. Each description contains two different space-separated integer numbers <span class=\"tex-span\"><i>v</i></span>, <span class=\"tex-span\"><i>u</i></span> (<span class=\"tex-span\">1โโคโ<i>v</i>โโคโ<i>n</i>,โ1โโคโ<i>u</i>โโคโ<i>n</i></span>) โ indexes of the points, joined by this segment. No segment is met in the description twice.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In the first line output number <span class=\"tex-span\"><i>k</i></span> โ amount of the segments in the answer. In the second line output <span class=\"tex-span\"><i>k</i></span> space-separated numbers โ indexes of these segments in ascending order. Each index should be output only once. Segments are numbered from 1 in the input order.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4 4<br />1 2<br />1 3<br />2 4<br />3 4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>4<br />1 2 3 4 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>4 5<br />1 2<br />2 3<br />3 4<br />4 1<br />1 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />5 </pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=E]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n <div style=\"text-align:center;\">\r\n <span class='contest-state-phase'>Before contest</span><br/><a href=\"/contests/1876,1877\">Codeforces Round 902 (Div. 2, based on COMPFEST 15 - Final Round)</a><br/><span class='countdown' home='//codeforces.org/s/81027' noRedirection='true' textBeforeRedirect=''>13:57:24</span><br/><a href=\"/contestRegistration/1877\">Register now ยป</a><div class=\"smaller notice\">*has extra registration<i class=\"icon-question-sign clickable-title\" title=\"If you are late to register in 5 minutes before the start, you can register later during the extra registration. Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='36b8243f0044940680edefae5a855cb6'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/YuukaKazami\">YuukaKazami</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/YuukaKazami\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/YuukaKazami\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/YuukaKazami\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/YuukaKazami\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/YuukaKazami\">Contests</a></li>\r\n <li><a\r\n href=\"/contests/writer/YuukaKazami\">Problemsetting</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/YuukaKazami\" style=\"text-decoration:none;color:black !important;\">YuukaKazami's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"559\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/559\"> Code Force Beta Round 19 Solution\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a>,\r\n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>,\r\n \r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><div style=\"text-align: left;\"><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 13.5pt;font-family: Simsun , serif;color: black;\">I find that no one write a solution about this contest..So I write one..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">A. World Football Cup</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">I think is' just a problem about writing codeย </span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">quickly and correctly.Just follow the statement.</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if you use c++ STL will make you life easier</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">B. Checkout Assistant</span><b><span lang=\"EN-US\" style=\"font-size: 21.5pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First,for every i increaseย t<sub>i</sub>ย by 1..then you will</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย see that statement require sum of t of the items<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">ย bigger or equal to n..and their sum of c shouldย <b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">be minimal..so it's just a 0-1 knapsack problem.<b></b></span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">C. Deletion of Repeats</span><b><span lang=\"EN-US\" style=\"font-size: 17.0pt;font-family: Verdana , sans-serif;color: black;\"></span></b></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First let's generate all repeats.In a repeat,the<br /> ย first number and the middle number must be theย <br /> same, so we just look at all pair of postion whichย <br /> have same number..Thank to the statement..Thereย <br /> are at most O(10N) such pair..And use suffix arrayย <br /> to check if each pair can build a repeat...Thenย <br /> just sort all the interval and go through then toย <br /> get the answer...<br /><a href=\"https://en.wikipedia.org/wiki/Suffix_array\">http://en.wikipedia.org/wiki/Suffix_array</a><br />maybe you think suffix array is hard to code..youย <br />can use hash and binary search to do the same..<br />my code hereย </span><a href=\"http://www.ideone.com/N5zPS\">http://www.ideone.com/N5zPS</a></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">D. Points<br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">First of all,do theย discretization.Then the biggestย <br /> value of x is n,so we can build a Segment Tree toย <br /> Ask the question "what is the first place from ย <br /> postion x and its value is bigger than y"..if weย <br /> find such postion we just find the smallest Y-valueย <br /> bigger than y in such postion--it can be done usingย <br /> set's operation upper_bound...<br /><a href=\"https://en.wikipedia.org/wiki/Segment_tree\">http://en.wikipedia.org/wiki/Segment_tree</a><br /> so the algorithm is clear..For every possible valueย <br /> of x use a set to store all y value in it..And everyย <br /> time the action is "find" or "remove" just changeย <br /> this set and update the Segment Tree..otherwise useย <br /> Segment Tree to find the answer..</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"></span><span style=\"font-family: Simsun , serif;font-size: 22.0px;\">my code hereย </span><a href=\"http://www.ideone.com/4iNol\">http://www.ideone.com/4iNol</a></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 19.0pt;font-family: Arial , sans-serif;color: black;\">E. Fairy</span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Arial , sans-serif;color: black;\"><br /> </span><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">It's a interesting problem.If you for every edge,ย <br /> try to remove it and check if it is aย bipartiteย <br /> graph..I think it will get TLE..so let'sย analysisย <br /> the property of bipartite graph..<br /><a href=\"https://en.wikipedia.org/wiki/Bipartite_graph\">http://en.wikipedia.org/wiki/Bipartite_graph</a><br />After reading it...we know..<br /> It should never contain a cycle of odd length...<br /> and it can be 2-colored..<br /> so first build aย spanning forest for the graph..<br /> and do the 2-color on it(Tree can be 2-colored).<br /> forย convenience.<br /> Let TreeEdge={all edge in forest}<br /> NotTreeEdge={All edge}/TreeEdge<br /> ErrorEdge={all edge that two endpoint have the same color..}<br /> NotErorEdge=NotTreeEdge/ErroEdge..<br /> First,consider a edge form NotTreeEdge,remove itย <br /> can't change any node's color..so..</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if |ErrorEdge|=0 of course we can remove all NotTreeEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if =1 we just can remove the ErrorEdge</span></p> <p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\">if >1 we can't remove any from NotTreeEdge<br /> Now,Let consider a Edge e from TreeEdge..<br /> Let Path(Edge e)=the path in forest between e's two endpoints..<br /> if there is a Edge e' from ErrorEdge that Path(e')ย <br /> didn't ย go through e..it will destroy the bipartiteย <br /> graph..<br /> if there is a Edge e' from ErrorEdge that Path(e') go through e and there is a Edge e'' from NotErrorEdge that Path(e'') go through e..it will also destroy the bipartite graph..<br /> so now we need to know for every edge,how many such path go through it..it require a data structure...<br /> one way is to use heavy-light decomposition then we can update every path in O(LogN^2)...<br /> another way is to use Link-Cut Tree..It can do the same in O(LogN)....<br />if you didn't see Link-Cut tree before,you can read this</span></p><p align=\"left\" style=\"text-align: left;\"><span lang=\"EN-US\" style=\"font-size: 14.0pt;font-family: Simsun , serif;color: black;\"><a href=\"https://en.wikipedia.org/wiki/Link/cut_tree\">http://www.cs.cmu.edu/~sleator/papers/dynamic-trees.pdf</a><br />or my code..use heavy-light decompositionย </span><a href=\"http://www.ideone.com/dPS5N\">http://www.ideone.com/dPS5N</a></p></div></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/19\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 19</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1664-559\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1664\",\n blogEntryId: \"559\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=solution\" class=\"tag notice\" style=\"text-decoration: none;\">solution</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+6</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-559\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/YuukaKazami\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/YuukaKazami\">\n YuukaKazami\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jul/29/2010 15:34\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/559#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/559#comments\">\n 22\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"569\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8814\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/freopen\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/769/avatar/4f63f1bce26e9eaf.jpg'/> </a>\n <div><a href=\"/profile/freopen\" title=\"Master freopen\" class=\"rated-user user-orange\">freopen</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 17:43\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8814\" href=\"?#comment-8814\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8814\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"769\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8814\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Why sizes of letters are not equal?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8814 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8814 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8814\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8821\" commentParentId=\"8814\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/YuukaKazami\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/582/avatar/ecf2f6ced3d15a2c.jpg'/> </a>\n <div><a href=\"/profile/YuukaKazami\" title=\"International Grandmaster YuukaKazami\" class=\"rated-user user-red\">YuukaKazami</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/29/2010 19:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8821\" href=\"?#comment-8821\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8814\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8821\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"582\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8821\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I don't know how to use the editor.. I'm ย trying to make it look nicer:)</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8821 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8821 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8821\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45545\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/MinakoKojima\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/7407/avatar/f0a7ee9c07f743b2.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/MinakoKojima\" title=\"Candidate Master MinakoKojima\" class=\"rated-user user-violet\">MinakoKojima</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 09:15\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45545\" href=\"?#comment-45545\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45545\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-6\"\r\n data-commentUserId=\"7407\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-6</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45545\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Orz...</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45545 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45545 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45545\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81107\" commentParentId=\"45545\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:06\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81107\" href=\"?#comment-81107\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-45545\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81107\" class=\"CommentVoteFrame\"\r\n class=\"negative-comment-vote\"\r\n data-commentRating=\"-13\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-13</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81107\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>What does it mean? Is it some Chinese abbreviation?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81107 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81107 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81107\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"81110\" commentParentId=\"81107\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/SirShokoladina\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/669/avatar/55c9f7be4f379bb7.jpg'/> </a>\n <div><a href=\"/profile/SirShokoladina\" title=\"International Grandmaster SirShokoladina\" class=\"rated-user user-red\">SirShokoladina</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/02/2012 11:14\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-81110\" href=\"?#comment-81110\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-81107\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"81110\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"669\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-81110\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I've found it myself.. "orz, a posture emoticon representing a kneeling, bowing, or comically fallen over person"</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-81110 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-81110 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-81110\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"45553\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2011 11:11\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-45553\" href=\"?#comment-45553\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"45553\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-45553\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">ym WJMZBMR!!!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-45553 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-45553 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-45553\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56504\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/cherudim\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/25704/avatar/697bcaedc1a7af08.jpg'/> </a>\n <div><a href=\"/profile/cherudim\" title=\"Master cherudim\" class=\"rated-user user-orange\">cherudim</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/26/2011 09:54\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56504\" href=\"?#comment-56504\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56504\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"25704\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56504\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">lovely english.....</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56504 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56504 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56504\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"820677\" commentParentId=\"56504\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/_CodeInfinity_\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/_CodeInfinity_\" title=\"Expert _CodeInfinity_\" class=\"rated-user user-blue\">_CodeInfinity_</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/25/2021 15:58\">2 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-820677\" href=\"?#comment-820677\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-56504\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"820677\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"-10\"\r\n data-commentUserId=\"2011039\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">-10</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-820677\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>yes </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-820677 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-820677 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-820677\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"56573\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Martin\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Martin\" title=\"Master Martin\" class=\"rated-user user-orange\">Martin</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/27/2011 07:48\">12 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-56573\" href=\"?#comment-56573\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"56573\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"399\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-56573\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">As a matter of fact, CF19E does not need a data structure, since we need not update it on-line. We can do it off-line with an easier way.<br />Path u-v can be divided to u-lca and v-lca, so add u, add v, and decrease lca by two. and that works.<br />More easily, we can use dfs-tree, to avoid looking for lca.<br />So the algorithm is O(n + m).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-56573 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-56573 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-56573\">\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"119638\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Faygoat\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/Faygoat\" title=\"Unrated, Faygoat\" class=\"rated-user user-black\">Faygoat</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jan/23/2013 10:04\">11 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-119638\" href=\"?#comment-119638\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"119638\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"80174\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-119638\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Anyone know if D can be solved using an augmented (self-balancing) binary search tree? To me, it does but I can't get a working solution. Any thoughts?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-119638 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-119638 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-119638\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"590081\" commentParentId=\"119638\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/Mooncrater\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/656776/avatar/d19b34b1e226e4ad.jpg'/> </a>\n <div><a href=\"/profile/Mooncrater\" title=\"Specialist Mooncrater\" class=\"rated-user user-cyan\">Mooncrater</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/18/2020 19:22\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-590081\" href=\"?#comment-590081\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-119638\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"590081\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"656776\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-590081\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>We don't do that here.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-590081 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-590081 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-590081\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347303\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/04/2017 22:13\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347303\" href=\"?#comment-347303\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347303\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347303\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Thanks for the solution!</p><p>In problem C, I think there are N*45 such pairs. // C(10,2)=45 Because you want not only the adjacant pairs. We need no suffix array nor hash. Just brute-force to compare the substrings is enough, thanks to the "no more than 10 times" constraint.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347303 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347303 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347303\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"347409\" commentParentId=\"347303\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/hpfdf\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/609/avatar/c1b9ba3bd350a91d.jpg'/> </a>\n <div><a href=\"/profile/hpfdf\" title=\"Master hpfdf\" class=\"rated-user user-orange\">hpfdf</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Mar/05/2017 15:40\">7 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-347409\" href=\"?#comment-347409\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347303\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"347409\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"609\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-347409\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Sorry this should be M*45, where M is the number of different letters appeared. So ~ N*4.5 in worst case. Thanks <a class=\"rated-user user-violet\" href=\"/profile/kokosha\" title=\"Candidate Master kokosha\">kokosha</a> for pointing out :)</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-347409 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-347409 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-347409\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"540078\" commentParentId=\"347409\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/roll_no_1\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/631859/avatar/36d157f91f64fe7f.jpg'/> </a>\n <div><a href=\"/profile/roll_no_1\" title=\"Master roll_no_1\" class=\"rated-user user-orange\">roll_no_1</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Sep/01/2019 21:26\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-540078\" href=\"?#comment-540078\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-347409\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"540078\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"631859\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-540078\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I think you're wrong here. There will be $$$M*10$$$ pairs. Consider we have $$$3$$$ indices $$$i, j, k$$$ for a character, where $$$i \\le j \\le k$$$. If the pair $$$(i, j)$$$ is a repeat and also $$$(i, k)$$$ is a repeat, then, we don't need to store $$$(i, k)$$$. This is because the pair $$$(i, j)$$$ has a smaller length and will be processed first after which, the substring starting at $$$i$$$ will be deleted. So, $$$(i, k)$$$ will never be processed. So, for every position $$$i$$$, we need only the closest position to the right $$$j$$$, s.t. $$$(i, j)$$$ is a repeat, i.e., substring of length $$$(j-i)$$$ starting at $$$i$$$ = substring of length $$$(j-i)$$$ starting at $$$j$$$. So, there are only $$$M*10 \\sim N$$$ pairs, that we need to store.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-540078 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-540078 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-540078\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"885642\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div style=\"position: absolute; left: 0;\" class=\"comment-indent-holder\">\r\n <div class=\"comment-no-indent\">\r\n <span>»</span>\r\n </div>\r\n </div>\r\n <div class=\"avatar\">\n <a href=\"/profile/lxylluvio\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/2152992/avatar/474fbab4d1688cf0.jpg'/> </a>\n <div><a href=\"/profile/lxylluvio\" title=\"Specialist lxylluvio\" class=\"rated-user user-cyan\">lxylluvio</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Feb/09/2022 12:21\">20 months ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-885642\" href=\"?#comment-885642\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"885642\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"5\"\r\n data-commentUserId=\"2152992\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+5</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-885642\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Why does my $$$\\tt{Edge}$$$ browser show $$$\\text{404 Not Found}$$$ when I click on the link <code>http://www.ideone.com/dPS5N</code>?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-885642 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-885642 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children 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BerOS file system"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. BerOS file system</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The new operating system BerOS has a nice feature. It is possible to use any number of characters <span class=\"tex-font-style-tt\">'/'</span> as a delimiter in path instead of one traditional <span class=\"tex-font-style-tt\">'/'</span>. For example, strings <span class=\"tex-font-style-tt\">//usr///local//nginx/sbin//</span> and <span class=\"tex-font-style-tt\">/usr/local/nginx///sbin</span> are equivalent. The character <span class=\"tex-font-style-tt\">'/'</span> (or some sequence of such characters) at the end of the path is required only in case of the path to the root directory, which can be represented as single character <span class=\"tex-font-style-tt\">'/'</span>.</p><p>A path called normalized if it contains the smallest possible number of characters <span class=\"tex-font-style-tt\">'/'</span>.</p><p>Your task is to transform a given path to the normalized form.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains only lowercase Latin letters and character <span class=\"tex-font-style-tt\">'/'</span>ย โ the path to some directory. All paths start with at least one character <span class=\"tex-font-style-tt\">'/'</span>. The length of the given line is no more than 100 characters, it is not empty.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>The path in normalized form.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>//usr///local//nginx/sbin<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>/usr/local/nginx/sbin<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"ff112d6f554b4da54c38769846af3c17\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"7522e0649e4511624d8f17b25e01c8d29b369701\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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=== ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_65b9c3d0518b67f9212fbb5c04360a319bf9bb57\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. BerOS file system</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>The new operating system BerOS has a nice feature. It is possible to use any number of characters <span class=\"tex-font-style-tt\">'/'</span> as a delimiter in path instead of one traditional <span class=\"tex-font-style-tt\">'/'</span>. For example, strings <span class=\"tex-font-style-tt\">//usr///local//nginx/sbin//</span> and <span class=\"tex-font-style-tt\">/usr/local/nginx///sbin</span> are equivalent. The character <span class=\"tex-font-style-tt\">'/'</span> (or some sequence of such characters) at the end of the path is required only in case of the path to the root directory, which can be represented as single character <span class=\"tex-font-style-tt\">'/'</span>.</p><p>A path called normalized if it contains the smallest possible number of characters <span class=\"tex-font-style-tt\">'/'</span>.</p><p>Your task is to transform a given path to the normalized form.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains only lowercase Latin letters and character <span class=\"tex-font-style-tt\">'/'</span>ย โ the path to some directory. All paths start with at least one character <span class=\"tex-font-style-tt\">'/'</span>. The length of the given line is no more than 100 characters, it is not empty.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>The path in normalized form.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>//usr///local//nginx/sbin<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>/usr/local/nginx/sbin<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n 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Equation"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Equation</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given an equation: </p><center> <span class=\"tex-span\"><i>Ax</i><sup class=\"upper-index\">2</sup>โ+โ<i>Bx</i>โ+โ<i>C</i>โ=โ0</span>. </center><p>Your task is to find the number of distinct roots of the equation and print all of them in ascending order.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains three integer numbers <span class=\"tex-span\"><i>A</i>,โ<i>B</i></span> and <span class=\"tex-span\"><i>C</i></span> (<span class=\"tex-span\">โ-โ10<sup class=\"upper-index\">5</sup>โโคโ<i>A</i>,โ<i>B</i>,โ<i>C</i>โโคโ10<sup class=\"upper-index\">5</sup></span>). Any coefficient may be equal to 0.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In case of infinite root count print the only integer <span class=\"tex-font-style-tt\">-1</span>. In case of no roots print the only integer <span class=\"tex-font-style-tt\">0</span>. In other cases print the number of root on the first line and the roots on the following lines in the ascending order. Print roots with at least 5 digits after the decimal point.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 -5 6<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/>2.0000000000<br/>3.0000000000</pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"973bb180c6266e8406fed362f34b1b28\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"7522e0649e4511624d8f17b25e01c8d29b369701\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/20/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='973bb180c6266e8406fed362f34b1b28'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"88\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = 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relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Equation</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given an equation: </p><center> <span class=\"tex-span\"><i>Ax</i><sup class=\"upper-index\">2</sup>โ+โ<i>Bx</i>โ+โ<i>C</i>โ=โ0</span>. </center><p>Your task is to find the number of distinct roots of the equation and print all of them in ascending order.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains three integer numbers <span class=\"tex-span\"><i>A</i>,โ<i>B</i></span> and <span class=\"tex-span\"><i>C</i></span> (<span class=\"tex-span\">โ-โ10<sup class=\"upper-index\">5</sup>โโคโ<i>A</i>,โ<i>B</i>,โ<i>C</i>โโคโ10<sup class=\"upper-index\">5</sup></span>). Any coefficient may be equal to 0.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>In case of infinite root count print the only integer <span class=\"tex-font-style-tt\">-1</span>. In case of no roots print the only integer <span class=\"tex-font-style-tt\">0</span>. In other cases print the number of root on the first line and the roots on the following lines in the ascending order. Print roots with at least 5 digits after the decimal point.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 -5 6<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br />2.0000000000<br />3.0000000000</pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n $problem.find(\".diff-notifier\").show();\r\n\r\n $problem.find(\".diff-notifier-close\").click(function() {\r\n Codeforces.putToStorageTtl(uuid, statementText, 6 * 60 * 60);\r\n 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Dijkstra?"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Dijkstra?</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a weighted undirected graph. The vertices are enumerated from 1 to <span class=\"tex-span\"><i>n</i></span>. Your task is to find the shortest path between the vertex <span class=\"tex-span\">1</span> and the vertex <span class=\"tex-span\"><i>n</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup>,โ0โโคโ<i>m</i>โโคโ10<sup class=\"upper-index\">5</sup></span>), where <span class=\"tex-span\"><i>n</i></span> is the number of vertices and <span class=\"tex-span\"><i>m</i></span> is the number of edges. Following <span class=\"tex-span\"><i>m</i></span> lines contain one edge each in form <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ<i>n</i>,โ1โโคโ<i>w</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">6</sup></span>), where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> are edge endpoints and <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> is the length of the edge.</p><p>It is possible that the graph has loops and multiple edges between pair of vertices.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Write the only integer <span class=\"tex-font-style-tt\">-1</span> in case of no path. Write the shortest path in opposite case. If there are many solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 6<br/>1 2 2<br/>2 5 5<br/>2 3 4<br/>1 4 1<br/>4 3 3<br/>3 5 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 4 3 5 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 6<br/>1 2 2<br/>2 5 5<br/>2 3 4<br/>1 4 1<br/>4 3 3<br/>3 5 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 4 3 5 </pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"248d8a243b5ead634f17e7e86c1d5f7a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"7522e0649e4511624d8f17b25e01c8d29b369701\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"C\" data-uuid=\"ps_7296bce3a3e6512d3c953ba01689de17a48a918f\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Dijkstra?</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given a weighted undirected graph. The vertices are enumerated from 1 to <span class=\"tex-span\"><i>n</i></span>. Your task is to find the shortest path between the vertex <span class=\"tex-span\">1</span> and the vertex <span class=\"tex-span\"><i>n</i></span>.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">2โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup>,โ0โโคโ<i>m</i>โโคโ10<sup class=\"upper-index\">5</sup></span>), where <span class=\"tex-span\"><i>n</i></span> is the number of vertices and <span class=\"tex-span\"><i>m</i></span> is the number of edges. Following <span class=\"tex-span\"><i>m</i></span> lines contain one edge each in form <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub></span>, <span class=\"tex-span\"><i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> and <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> (<span class=\"tex-span\">1โโคโ<i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ<i>n</i>,โ1โโคโ<i>w</i><sub class=\"lower-index\"><i>i</i></sub>โโคโ10<sup class=\"upper-index\">6</sup></span>), where <span class=\"tex-span\"><i>a</i><sub class=\"lower-index\"><i>i</i></sub>,โ<i>b</i><sub class=\"lower-index\"><i>i</i></sub></span> are edge endpoints and <span class=\"tex-span\"><i>w</i><sub class=\"lower-index\"><i>i</i></sub></span> is the length of the edge.</p><p>It is possible that the graph has loops and multiple edges between pair of vertices.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Write the only integer <span class=\"tex-font-style-tt\">-1</span> in case of no path. Write the shortest path in opposite case. If there are many solutions, print any of them.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 6<br />1 2 2<br />2 5 5<br />2 3 4<br />1 4 1<br />4 3 3<br />3 5 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 4 3 5 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 6<br />1 2 2<br />2 5 5<br />2 3 4<br />1 4 1<br />4 3 3<br />3 5 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 4 3 5 </pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if 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</script>\n</div>\n <script type=\"application/javascript\">\n if ('serviceWorker' in navigator && 'fetch' in window && 'caches' in window) {\n navigator.serviceWorker.register('/service-worker-73366.js')\n .then(function (registration) {\n console.log('Service worker registered: ', registration);\n })\n .catch(function (error) {\n console.log('Registration failed: ', error);\n });\n }\n </script>\n<script>(function(){var js = \"window['__CF$cv$params']={r:'812286737bfc7a6d',t:'MTY5NjY0Mzc2MS4yODIwMDA='};_cpo=document.createElement('script');_cpo.nonce='',_cpo.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js',document.getElementsByTagName('head')[0].appendChild(_cpo);\";var _0xh = document.createElement('iframe');_0xh.height = 1;_0xh.width = 1;_0xh.style.position = 'absolute';_0xh.style.top = 0;_0xh.style.left = 0;_0xh.style.border = 'none';_0xh.style.visibility = 'hidden';document.body.appendChild(_0xh);function handler() {var _0xi = _0xh.contentDocument || 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\"*1900\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":92,"cells":{"problem_id":{"kind":"string","value":"21A"},"contest":{"kind":"string","value":"21"},"problem":{"kind":"string","value":"A"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"A. Jabber ID"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Jabber ID</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Jabber ID on the national Berland service ยซBabberยป has a form <span class=\"tex-font-style-tt\"><username>@<hostname>[/resource]</span>, where </p><ul> <li> <span class=\"tex-font-style-tt\"><username></span> โ is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters ยซ<span class=\"tex-font-style-tt\">_</span>ยป, the length of <span class=\"tex-font-style-tt\"><username></span> is between 1 and 16, inclusive. </li><li> <span class=\"tex-font-style-tt\"><hostname></span> โ is a sequence of word separated by periods (characters ยซ<span class=\"tex-font-style-tt\">.</span>ยป), where each word should contain only characters allowed for <span class=\"tex-font-style-tt\"><username></span>, the length of each word is between 1 and 16, inclusive. The length of <span class=\"tex-font-style-tt\"><hostname></span> is between 1 and 32, inclusive. </li><li> <span class=\"tex-font-style-tt\"><resource></span> โ is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters ยซ<span class=\"tex-font-style-tt\">_</span>ยป, the length of <span class=\"tex-font-style-tt\"><resource></span> is between 1 and 16, inclusive. </li></ul><p>The content of square brackets is optional โ it can be present or can be absent.</p><p>There are the samples of correct Jabber IDs: <span class=\"tex-font-style-tt\"><a class=\"__cf_email__\" data-cfemail=\"1c717577795c7f7378797a736e7f796f327f7371\" href=\"/cdn-cgi/l/email-protection\">[emailย protected]</a></span>, <span class=\"tex-font-style-tt\"><a class=\"__cf_email__\" data-cfemail=\"1b2b2b2c5b7e753578747f7e7d7469787e6835787476\" href=\"/cdn-cgi/l/email-protection\">[emailย protected]</a>/contest</span>.</p><p>Your task is to write program which checks if given string is a correct Jabber ID.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input contains of a single line. The line has the length between 1 and 100 characters, inclusive. Each characters has ASCII-code between 33 and 127, inclusive.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-font-style-tt\">YES</span> or <span class=\"tex-font-style-tt\">NO</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre><a class=\"__cf_email__\" data-cfemail=\"dfb2b6b4ba9fbcb0bbbab9b0adbcbaacf1bcb0b2\" href=\"/cdn-cgi/l/email-protection\">[emailย protected]</a><br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre><a class=\"__cf_email__\" data-cfemail=\"5e34313630702d33372a361e3d313a3b38312c3d3b2d702c2b\" href=\"/cdn-cgi/l/email-protection\">[emailย protected]</a>/contest.icpc/12<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"62792626563ec00f5ae323f28db0d69a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b4a339edd268d11f165cc4c15ec8e6598fc84598\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Jabber ID</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Jabber ID on the national Berland service ยซBabberยป has a form <span class=\"tex-font-style-tt\"><username>@<hostname>[/resource]</span>, where </p><ul> <li> <span class=\"tex-font-style-tt\"><username></span> โ is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters ยซ<span class=\"tex-font-style-tt\">_</span>ยป, the length of <span class=\"tex-font-style-tt\"><username></span> is between 1 and 16, inclusive. </li><li> <span class=\"tex-font-style-tt\"><hostname></span> โ is a sequence of word separated by periods (characters ยซ<span class=\"tex-font-style-tt\">.</span>ยป), where each word should contain only characters allowed for <span class=\"tex-font-style-tt\"><username></span>, the length of each word is between 1 and 16, inclusive. The length of <span class=\"tex-font-style-tt\"><hostname></span> is between 1 and 32, inclusive. </li><li> <span class=\"tex-font-style-tt\"><resource></span> โ is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters ยซ<span class=\"tex-font-style-tt\">_</span>ยป, the length of <span class=\"tex-font-style-tt\"><resource></span> is between 1 and 16, inclusive. </li></ul><p>The content of square brackets is optional โ it can be present or can be absent.</p><p>There are the samples of correct Jabber IDs: <span class=\"tex-font-style-tt\"><a href=\"/cdn-cgi/l/email-protection\" class=\"__cf_email__\" data-cfemail=\"1c717577795c7f7378797a736e7f796f327f7371\">[email protected]</a></span>, <span class=\"tex-font-style-tt\"><a href=\"/cdn-cgi/l/email-protection\" class=\"__cf_email__\" data-cfemail=\"1b2b2b2c5b7e753578747f7e7d7469787e6835787476\">[email protected]</a>/contest</span>.</p><p>Your task is to write program which checks if given string is a correct Jabber ID.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The input contains of a single line. The line has the length between 1 and 100 characters, inclusive. Each characters has ASCII-code between 33 and 127, inclusive.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print <span class=\"tex-font-style-tt\">YES</span> or <span class=\"tex-font-style-tt\">NO</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre><a href=\"/cdn-cgi/l/email-protection\" class=\"__cf_email__\" data-cfemail=\"dfb2b6b4ba9fbcb0bbbab9b0adbcbaacf1bcb0b2\">[email protected]</a><br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>YES<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre><a href=\"/cdn-cgi/l/email-protection\" class=\"__cf_email__\" data-cfemail=\"5e34313630702d33372a361e3d313a3b38312c3d3b2d702c2b\">[email protected]</a>/contest.icpc/12<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>NO<br 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{document.onreadystatechange = prev;handler();}};}})();</script></body>\n</html>\n"},"long_tags":{"kind":"string","value":"[\"Implementation problems, programming technics, simulation\", \"Prefix- and Z-functions, suffix structures, Knuth\\u2013Morris\\u2013Pratt algorithm, etc\"]"},"short_tags":{"kind":"string","value":"[\"implementation\", \"strings\", \"*1900\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":93,"cells":{"problem_id":{"kind":"string","value":"21B"},"contest":{"kind":"string","value":"21"},"problem":{"kind":"string","value":"B"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"B. Intersection"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Intersection</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given two set of points. The first set is determined by the equation <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">1</sub><i>x</i>โ+โ<i>B</i><sub class=\"lower-index\">1</sub><i>y</i>โ+โ<i>C</i><sub class=\"lower-index\">1</sub>โ=โ0</span>, and the second one is determined by the equation <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">2</sub><i>x</i>โ+โ<i>B</i><sub class=\"lower-index\">2</sub><i>y</i>โ+โ<i>C</i><sub class=\"lower-index\">2</sub>โ=โ0</span>.</p><p>Write the program which finds the number of points in the intersection of two given sets.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains three integer numbers <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">1</sub>,โ<i>C</i><sub class=\"lower-index\">1</sub></span> separated by space. The second line contains three integer numbers <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">2</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>,โ<i>C</i><sub class=\"lower-index\">2</sub></span> separated by space. All the numbers are between -100 and 100, inclusive.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the number of points in the intersection or <span class=\"tex-font-style-tt\">-1</span> if there are infinite number of points.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 0<br/>2 2 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 0<br/>2 -2 0<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"ce7f23b6691badefb891c2e27a65901a\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b4a339edd268d11f165cc4c15ec8e6598fc84598\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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class=\"header\"><div class=\"title\">B. Intersection</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given two set of points. The first set is determined by the equation <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">1</sub><i>x</i>โ+โ<i>B</i><sub class=\"lower-index\">1</sub><i>y</i>โ+โ<i>C</i><sub class=\"lower-index\">1</sub>โ=โ0</span>, and the second one is determined by the equation <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">2</sub><i>x</i>โ+โ<i>B</i><sub class=\"lower-index\">2</sub><i>y</i>โ+โ<i>C</i><sub class=\"lower-index\">2</sub>โ=โ0</span>.</p><p>Write the program which finds the number of points in the intersection of two given sets.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains three integer numbers <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">1</sub>,โ<i>B</i><sub class=\"lower-index\">1</sub>,โ<i>C</i><sub class=\"lower-index\">1</sub></span> separated by space. The second line contains three integer numbers <span class=\"tex-span\"><i>A</i><sub class=\"lower-index\">2</sub>,โ<i>B</i><sub class=\"lower-index\">2</sub>,โ<i>C</i><sub class=\"lower-index\">2</sub></span> separated by space. All the numbers are between -100 and 100, inclusive.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Print the number of points in the intersection or <span class=\"tex-font-style-tt\">-1</span> if there are infinite number of points.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 0<br />2 2 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>1 1 0<br />2 -2 0<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = 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\"*2000\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":94,"cells":{"problem_id":{"kind":"string","value":"21C"},"contest":{"kind":"string","value":"21"},"problem":{"kind":"string","value":"C"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"C. Stripe 2"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Stripe 2</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob took a paper stripe of n squares (the height of the stripe is 1 square). In each square he wrote an integer number, possibly negative. He became interested in how many ways exist to cut this stripe into three pieces so that the sum of numbers from each piece is equal to the sum of numbers from any other piece, and each piece contains positive integer amount of squares. Would you help Bob solve this problem?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ amount of squares in the stripe. The second line contains n space-separated numbers โ they are the numbers written in the squares of the stripe. These numbers are integer and do not exceed 10000 in absolute value.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the amount of ways to cut the stripe into three non-empty pieces so that the sum of numbers from each piece is equal to the sum of numbers from any other piece. Don't forget that it's allowed to cut the stripe along the squares' borders only.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>1 2 3 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 2 3 4 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"5b827220500ab8b739dcc38afc3aa999\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b4a339edd268d11f165cc4c15ec8e6598fc84598\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='5b827220500ab8b739dcc38afc3aa999'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/21/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Binary search\">\r\n binary search\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Dynamic programming\">\r\n dp\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *2000\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='5b827220500ab8b739dcc38afc3aa999'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"97\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='5b827220500ab8b739dcc38afc3aa999'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"97\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 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both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/21\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/21/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/21/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/21/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/21/hacks\">Hacks</a></li>\r\n <li><a\r\n href=\"/contest/21/room/1\">Room</a></li>\r\n <li><a\r\n href=\"/contest/21/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/21/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem 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class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. Stripe 2</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob took a paper stripe of n squares (the height of the stripe is 1 square). In each square he wrote an integer number, possibly negative. He became interested in how many ways exist to cut this stripe into three pieces so that the sum of numbers from each piece is equal to the sum of numbers from any other piece, and each piece contains positive integer amount of squares. Would you help Bob solve this problem?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup></span>) โ amount of squares in the stripe. The second line contains n space-separated numbers โ they are the numbers written in the squares of the stripe. These numbers are integer and do not exceed 10000 in absolute value.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output the amount of ways to cut the stripe into three non-empty pieces so that the sum of numbers from each piece is equal to the sum of numbers from any other piece. Don't forget that it's allowed to cut the stripe along the squares' borders only.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />1 2 3 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 2 3 4 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>0<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n 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\"*2000\"]"},"tutorial_link":{"kind":"string","value":""},"tutorial_page":{"kind":"string","value":""}}},{"rowIdx":95,"cells":{"problem_id":{"kind":"string","value":"21D"},"contest":{"kind":"string","value":"21"},"problem":{"kind":"string","value":"D"},"lang":{"kind":"string","value":"en"},"problem_title":{"kind":"string","value":"D. Traveling Graph"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Traveling Graph</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given undirected weighted graph. Find the length of the shortest cycle which starts from the vertex 1 and passes throught all the edges at least once. Graph may contain multiply edges between a pair of vertices and loops (edges from the vertex to itself).</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ15,โ0โโคโ<i>m</i>โโคโ2000</span>), <span class=\"tex-span\"><i>n</i></span> is the amount of vertices, and <span class=\"tex-span\"><i>m</i></span> is the amount of edges. Following <span class=\"tex-span\"><i>m</i></span> lines contain edges as a triples <span class=\"tex-span\"><i>x</i>,โ<i>y</i>,โ<i>w</i></span> (<span class=\"tex-span\">1โโคโ<i>x</i>,โ<i>y</i>โโคโ<i>n</i>,โ1โโคโ<i>w</i>โโคโ10000</span>), <span class=\"tex-span\"><i>x</i>,โ<i>y</i></span> are edge endpoints, and <span class=\"tex-span\"><i>w</i></span> is the edge length.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output minimal cycle length or <span class=\"tex-font-style-tt\">-1</span> if it doesn't exists.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>1 2 1<br/>2 3 1<br/>3 1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br/>1 2 3<br/>2 3 4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>14<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"fb06fae9b5ff44c974e3833c8d612905\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"b4a339edd268d11f165cc4c15ec8e6598fc84598\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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\"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_31e9bb7ee8cf12cd6654a2188352501b1281148f\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Traveling Graph</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>0.5 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>64 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given undirected weighted graph. Find the length of the shortest cycle which starts from the vertex 1 and passes throught all the edges at least once. Graph may contain multiply edges between a pair of vertices and loops (edges from the vertex to itself).</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains two integers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ15,โ0โโคโ<i>m</i>โโคโ2000</span>), <span class=\"tex-span\"><i>n</i></span> is the amount of vertices, and <span class=\"tex-span\"><i>m</i></span> is the amount of edges. Following <span class=\"tex-span\"><i>m</i></span> lines contain edges as a triples <span class=\"tex-span\"><i>x</i>,โ<i>y</i>,โ<i>w</i></span> (<span class=\"tex-span\">1โโคโ<i>x</i>,โ<i>y</i>โโคโ<i>n</i>,โ1โโคโ<i>w</i>โโคโ10000</span>), <span class=\"tex-span\"><i>x</i>,โ<i>y</i></span> are edge endpoints, and <span class=\"tex-span\"><i>w</i></span> is the edge length.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output minimal cycle length or <span class=\"tex-font-style-tt\">-1</span> if it doesn't exists.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />1 2 1<br />2 3 1<br />3 1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>3 2<br />1 2 3<br />2 3 4<br /></pre></div><div class=\"output\"><div 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Second Order Statistics"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Second Order Statistics</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob needed to find the second order statistics of a sequence of integer numbers. Lets choose each number from the sequence exactly once and sort them. The value on the second position is the second order statistics of the given sequence. In other words it is the smallest element strictly greater than the minimum. Help Bob solve this problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ100</span>) โ amount of numbers in the sequence. The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integer numbers โ elements of the sequence. These numbers don't exceed 100 in absolute value.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the given sequence has the second order statistics, output this order statistics, otherwise output <span class=\"tex-font-style-tt\">NO</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br/>1 2 2 -4<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>1 2 3 1 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"7d0720cc9b2fae6263015c0b52bcecd0\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - A - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"78ba613a0b107244c6d0594b0c9efe02d4e7cf63\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - A - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/22\">Codeforces Beta Round 22 (Div. 2 Only)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='7d0720cc9b2fae6263015c0b52bcecd0'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/22/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Brute force\">\r\n brute force\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *800\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7d0720cc9b2fae6263015c0b52bcecd0'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"99\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='7d0720cc9b2fae6263015c0b52bcecd0'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"99\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") {\r\n $(\"#addTagLabel\").hide();\r\n $(\"#addTagLink\").show();\r\n } else {\r\n $(\"#addTagForm input[name=tagName]\").val(tagName);\r\n $(\"#addTagForm\").submit();\r\n }\r\n });\r\n</script>\r\n\r\n<style type=\"text/css\">\r\n#new-resource-form tr td {\r\npadding-top: 0.5em;\r\n}\r\n#new-resource-form input:not([type=\"submit\"]) {\r\nfont-size: 0.8em;\r\n}\r\n#new-resource-form select {\r\nfont-size: 0.8em;\r\n}\r\n.new-resource-error {\r\nfont-size: 0.8em;\r\n}\r\n.resource-locale {\r\ncolor: #666;\r\nfont-family: Consolas, \"Andale Mono WT\", \"Andale Mono\", \"Lucida Console\", \"Lucida Sans Typewriter\", \"DejaVu Sans Mono\", \"Bitstream Vera Sans Mono\", \"Liberation Mono\", \"Nimbus Mono L\", Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/505\" title=\"Codeforces Beta Round #22 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"109:110\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/507\" title=\"Codeforces Beta Round #22 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"459:460\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/22\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/22/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/22/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/22/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/22/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/22/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: absolute;\r\n font-weight: bold;\r\n font-size: 1rem;\r\n }\r\n\r\n .diff-popup {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n display: none;\r\n overflow: auto;\r\n }\r\n\r\n .input-output-copier {\r\n font-size: 1.2rem;\r\n float: right;\r\n color: #888 !important;\r\n cursor: pointer;\r\n border: 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&& node.tagName === \"BR\") {\r\n result.push(\"\\n\");\r\n }\r\n\r\n node.childNodes.forEach(function (child) {\r\n result.push(nodeToText(child, node.tagName === \"PRE\").join(\"\"));\r\n });\r\n\r\n if (node.tagName === \"DIV\"\r\n || node.tagName === \"P\"\r\n || node.tagName === \"PRE\"\r\n || node.tagName === \"UL\"\r\n || node.tagName === \"LI\"\r\n ) {\r\n result.push(\"\\n\");\r\n }\r\n\r\n if (node.tagName === \"NOBR\") {\r\n result.push(CLOSING_SPACE);\r\n }\r\n\r\n return result;\r\n }\r\n\r\n const isSpecial = function (c) {\r\n return c === ',' || c === '.' || c === ';' || c === ')' || c === ' ';\r\n }\r\n\r\n const convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"A\" data-uuid=\"ps_1ed615cc946df65f43e372691cc909bd57410b6d\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">A. Second Order Statistics</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Once Bob needed to find the second order statistics of a sequence of integer numbers. Lets choose each number from the sequence exactly once and sort them. The value on the second position is the second order statistics of the given sequence. In other words it is the smallest element strictly greater than the minimum. Help Bob solve this problem.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains integer <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ100</span>) โ amount of numbers in the sequence. The second line contains <span class=\"tex-span\"><i>n</i></span> space-separated integer numbers โ elements of the sequence. These numbers don't exceed 100 in absolute value.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If the given sequence has the second order statistics, output this order statistics, otherwise output <span class=\"tex-font-style-tt\">NO</span>.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>4<br />1 2 2 -4<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />1 2 3 1 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>2<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=A]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = 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$(document).ready(function () {\r\n window.changedTests = new Set();\r\n\r\n function endsWith(string, suffix) {\r\n return string.indexOf(suffix, string.length - suffix.length) !== -1;\r\n }\r\n\r\n const inputFileDiv = $(\"div.input-file\");\r\n const inputFile = inputFileDiv.text();\r\n const outputFileDiv = $(\"div.output-file\");\r\n const outputFile = outputFileDiv.text();\r\n\r\n\r\n if (!endsWith(inputFile, \"standard input\")\r\n && !endsWith(inputFile, \"standard input\")) {\r\n inputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n if (!endsWith(outputFile, \"standard output\")\r\n && !endsWith(outputFile, \"standard output\")) {\r\n outputFileDiv.attr(\"style\", \"font-weight: bold\");\r\n }\r\n\r\n const titleDiv = $(\"div.header div.title\");\r\n\r\n\r\n\r\n String.prototype.replaceAll = function (search, replace) {\r\n return this.split(search).join(replace);\r\n };\r\n\r\n $(\".sample-test .title\").each(function () {\r\n const preId = (\"id\" + 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$(\".test-form-item input\").change(function () {\r\n addPendingSubmissionMessage($($(this).closest(\"form\")), \"You changed the answer, do not forget to submit it if you want to save the changes\");\r\n const index = $(this).closest(\".problemindexholder\").attr(\"problemindex\");\r\n let test = \"\";\r\n $(this).closest(\"form input\").each(function () {\r\n const test_ = $(this).attr(\"name\");\r\n if (test_ && test_.substring(0, 4) === \"test\") {\r\n test = test_;\r\n }\r\n });\r\n if (index.length > 0 && test.length > 0) {\r\n const indexTest = index + \"::\" + test;\r\n window.changedTests.add(indexTest);\r\n }\r\n });\r\n\r\n $(window).on('beforeunload', function () {\r\n if (window.changedTests.size > 0) {\r\n return 'Dialog text here';\r\n }\r\n });\r\n\r\n autosize($('.test-explanation textarea'));\r\n\r\n $(\".test-example-line\").hover(function() {\r\n $(this).attr(\"class\").split(\" \").forEach((clazz) => {\r\n if (clazz.substr(0, \"test-example-line-\".length) === 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Extra registration opens 10 minutes after the contest starts and lasts 25 minutes.\"></i></div>\r\n </div>\r\n</div>\r\n </div>\n\n<style data-nocturne=\"true\" type=\"text/css\">\n._StreamsSidebarFrame_frame {\n padding: 0.5em 0.5em 0 0.5em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream {\n text-align: center;\n border-bottom: 1px solid #b9b9b9;\n margin: 0 -0.5em 0.5em -0.5em;\n padding: 0 1em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_user {\n margin: 0 0 0.5em 0;\n font-size: 0.8em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream ._StreamsSidebarFrame_timeMark {\n color: #777;\n font-size: 0.9em;\n}\n._StreamsSidebarFrame_frame ._StreamsSidebarFrame_stream:last-of-type {\n border-bottom: unset;\n margin: unset;\n padding: 0 0.5em 0.5em 1em;\n}\n._StreamsSidebarFrame_frame ._viewAll {\n text-align: right;\n}\n.moreRunningStreamsSidebarNote {\n color: #777 !important;\n text-decoration: none;\n}\n</style>\n\n\n<script data-nocturne=\"true\"> $(function () {\n\n}); </script>\n\n<div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Top rated\n<div class=\"top-links\">\n</div>\n</div>\n<table class=\"rtable \">\n<tbody>\n<tr>\n<th class=\"left\" style=\"width:2.25em;\">#</th>\n<th class=\"\">User</th>\n<th class=\"\" style=\"width:5em;\">Rating</th>\n</tr>\n<tr>\n<td class=\"left dark\">1</td>\n<td class=\" dark\"><a href=\"/profile/tourist\" title=\"Legendary Grandmaster tourist\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">t</span>ourist</a></td>\n<td class=\" dark\">3775</td>\n</tr>\n<tr>\n<td class=\"left \">2</td>\n<td class=\"\"><a href=\"/profile/Benq\" title=\"Legendary Grandmaster Benq\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">B</span>enq</a></td>\n<td class=\"\">3724</td>\n</tr>\n<tr>\n<td class=\"left dark\">3</td>\n<td class=\" dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='24bfa389977bffbbea433287f885534f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n </label>\r\n </div>\r\n <div style=\"padding: 0 1em 1em 1em;text-align:right;\">\r\n <input style=\"height:1.65em;padding:0 0.75em;\" type=\"submit\" value=\"Find\"/>\r\n </div>\r\n </form>\r\n </div>\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".handleBox\").autocomplete(\"/data/handles\", {\r\n delay: 200,\r\n width: 200,\r\n selectFirst: false,\r\n matchContains: true,\r\n minChars: 3\r\n });\r\n $(\".handleForm\").attr(\"autocomplete\", \"off\").submit(function () {\r\n var link = \"/profile/userHandle\".replace(\r\n \"userHandle\", $(this).find(\".handleBox\").val()\r\n );\r\n window.location = link;\r\n return false;\r\n });\r\n });\n </script>\n\r\n\r\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Recent actions\n <div class=\"top-links\">\n </div>\n </div>\n <div class=\"recent-actions\">\r\n <ul>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a> →\r\n <a href=\"/blog/entry/121073\">Meta Hacker Cup 2023 Round 1</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pyqe\" title=\"International Grandmaster Pyqe\" class=\"rated-user user-red\">Pyqe</a> →\r\n <a href=\"/blog/entry/121025\">Codeforces Round #902 (Div. 1, Div. 2, based on COMPFEST 15 โ Final Round)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/Pranshu_Pandya\" title=\"Specialist Pranshu_Pandya\" class=\"rated-user user-cyan\">Pranshu_Pandya</a> →\r\n <a href=\"/blog/entry/121171\">An Interesting Tree Problem</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/.Danet\" title=\"Expert .Danet\" class=\"rated-user user-blue\">.Danet</a> →\r\n <a href=\"/blog/entry/121172\">[TLE on pretest1]</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" style=\"vertical-align:middle;\"/>\r\n</div>\r\n</li>\r\n <li><div style=\"font-size:0.9em;padding:0.5em 0;\">\r\n<a href=\"/profile/sszcdjr\" title=\"Master sszcdjr\" class=\"rated-user user-orange\">sszcdjr</a> →\r\n <a href=\"/blog/entry/119859\">Codeforces Round 896 (Div. 1, Div. 2)</a>\r\n <img alt=\"New comment(s)\" title=\"New comment(s)\" src=\"//codeforces.org/s/81027/images/icons/comment-12x12.png\" 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title=\"Jun/29/2010 22:08\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"//codeforces.com/blog/entry/505\">Contest discussion</a></p><h3><strong>Problem ะ. Second Order Statistics</strong></h3><p><u>Sorting</u></p><p>In this problem one should find a minimal element from all elements, that are strictly greater, then the minimal one or report that it doesn't exist. Of course, there can be a lot of different solutions, but one of the simplest - to sort the given sequence and print the first element, that's not equal to the previous. If all elements are equal, then the required element doesn't exist.<strong><br /></strong></p><p> </p><h3>Problem B. Bargaining Table</h3><p><u>Simulation, dynamic programming</u></p><p>In this problem one should find the maximal perimeter of a rectangle that contains no '1'. Define these rectangles "correct". To solve a problem you are to check each possible rectangle for correctness and calculate its perimeter. The easiest way to check all rectangles is using 6 nested cycles. Using 4 of them you fix the coordinates while other 2 will look for '1'. So the complexity is O((n*m)<sup>3</sup>). It seems slow, but those, who wrote such a solution, says that it hasn't any problems with TL.<u><br /></u></p><p>One may interest in much faster solution. Using simple DP solution one can get a solution with an O((n*m)<sup>2</sup>) complexity. It's clear, that rectangle with coordinates (x1, y1, x2, y2) is correct if and only if rectangles (x1, y1, x2-1, y2) and (x1, y1, x2, y2-1) are correct, and board[x2][y2] = '0'. So each of rectangles can be checked in O(1) and totally there will be O((n*m)<sup>2</sup>) operations.</p><h3>Problem C. System Administrator</h3><p><u>Simulation</u></p><p>In this problem you are to construct a connected graph, which contains n vertexes and m edges, and if we delete vertex with number v, our graph stops being connected or to report that such a graph doesn't exist. Moreover, each pair of vertexes can have no more than one edge connecting them. Obviously, a connected graph doesn't exist if the number of edges is less than n-1. It's easy to notice, that the maximal possible number of edges reaches when there is a vertex connected to v and doesn't connected to any other vertex, those can form up to complete graph. So the maximal number of edges is (n-1)*(n-2)/2+1. If m is in that range then required graph always exists. Then you should place one vertex on the one side of v (let it be 1), and other vertexes - on the other side. First, you should connect all this vertexes to v and then connect them between each other (except 1).<u><br /></u></p><h3>Problem D. Segments</h3><p><u>Scanning line</u></p><p>In this problem one should place minimal number of points on the line such that any given segment touches at least one of these points. Let's call the coordinate of ending of any segment as event. There will be events of two types: beginning of a segment and its ending. Let's sort this events by coordinates. In the case of equality of some events consider that the event of the beginning will be less than the event of ending. Look at our events from left to right: if there is a beginning event, then push the number of this segment to the special queue. Once we take an ending of some segment, place the point here and clear the special queue (because each of segment in this queue will touch this point).<u><br /></u></p><h3>Problem E. Scheme</h3><p><u>Graph theory</u></p><p>Given an oriented graph, find the minimal number of edges one should add to this graph to make it strongly connected. Looking at statement we can get the fact that each vertex has exactly one outcoming edge. It means that starting at some point we'll get stuck in some cycle. So each connected (not strongly) component is a set of simple paths, ending in some cycle or just a simple cycle. First consider vertexes, which has no incoming edges. When passing through some vertex we'll paint it until the current vertex will be already painted. Then we call the starting vertex as "beginning" and the finishing one as "ending" of a component.<u><br /></u></p><p>After that consider other vertexes - they belong to cycles. Beginning and ending of a cycle - is any vertexes (possible coinciding) belonging to it. So we got a number of components which we have to connect. Let's connect them cyclically: the edge will pass from the ending of i-th component to the beginning of ((i+1)%k)-th, where k is the number of such components. The answer will be k. There is an exception: if we have only one component which is a simple cycle, the answer will be equal to 0.</p><p>So we'll consider each edge exactly once and the total complexity will be O(n).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/22\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 22 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1448-507\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1448\",\n blogEntryId: \"507\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2322\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #22</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+32</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/iakolzin\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/iakolzin\">\n iakolzin\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/507#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/507#comments\">\n 18\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"517\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7927\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/30/2010 22:30\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7927\" href=\"?#comment-7927\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7927\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7927\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Some of your types seem incorrect... Problems B and C are not simulation. Simulation involves running some sort of given process (usually efficiently), and neither of these problems involve that. B is brute force / DP, and C is graph theory.<br /><br />But the tutorial is great, thanks :) I can go fix my E now :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7927 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7927 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7927\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7943\" commentParentId=\"7927\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/yangfan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yangfan\" title=\"Specialist yangfan\" class=\"rated-user user-cyan\">yangfan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 02:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7943\" href=\"?#comment-7943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7927\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4604\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I am not solving E with tutorial's method, and I got Wrong Answer on test 15 for a long time. Did U get any trouble on test 15? Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7956\" commentParentId=\"7943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 07:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7956\" href=\"?#comment-7956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://piratepad.net/ZosxPMMqyK<br /><br />There's my code for it. It passes 15, but gets RE on Test 22. I'm really not sure why. Tell me if you can find it, and hopefully it helps you with yours!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7965\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 12:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7965\" href=\"?#comment-7965\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7965\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7965\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You have stack overflow in dfs. Stack for default thread in java is not very big, you can avoid it by creating your own thread and executing code in it, like<div>class Sample implements Runnable {</div><div><span style=\"white-space: pre;\"> </span>public static void main(String[] args) {</div><div><span style=\"white-space: pre;\"> </span>new Thread(new Sample()).start();</div><div><span style=\"white-space: pre;\"> </span>}</div><div><br /></div><div><span style=\"white-space: pre;\"> </span>public void run() {</div><div><span style=\"white-space: pre;\"> </span>//Solution here</div><div><span style=\"white-space: pre;\"> </span>}</div><div>}</div><div><br /></div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7965 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7965 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7965\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7980\" commentParentId=\"7965\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 20:29\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7980\" href=\"?#comment-7980\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7965\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7980\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7980\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks (to Ivan too)!<br /><br />I really shouldn't have missed that... though I didn't know that a new Thread could get extra stack space. Most interesting.<br /><br />I've got AC now and I've updated my code :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7980 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7980 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7980\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7973\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ivan.popelyshev\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73/avatar/dcae35722510f549.jpg'/> </a>\n <div><a href=\"/profile/ivan.popelyshev\" title=\"Master ivan.popelyshev\" class=\"rated-user user-orange\">ivan.popelyshev</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 16:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7973\" href=\"?#comment-7973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"73\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">new Thread(null, new Sample(), "1", 1<<23).start(); - 8 megabytes stack.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8053\" href=\"?#comment-8053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">problem C may also be solved using a stack + dp, which gives an extremely fast O(mn) solution</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8053\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8054\" commentParentId=\"8053\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8054\" href=\"?#comment-8054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8053\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">*problem B<div><br /></div><div>ps: there really should be an edit function for comments</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8133\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2010 20:03\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8133\" href=\"?#comment-8133\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8133\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8133\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you give more details for the O(mn) solution?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8133 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8133 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8133\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8142\" commentParentId=\"8133\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 00:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8142\" href=\"?#comment-8142\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8133\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8142\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8142\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">its a fairly standard solution<br />its the same as the "largest rectangle in a histogram" problem except now you're looking for maximal perimeter, and you need to do a dp preprocessing<br />the "largest rectangle in a histogram" solution is here: http://homeofcox-cs.blogspot.com/2010/04/max-rectangle-in-histogram-problem.html</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8142 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8142 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8142\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662663\" commentParentId=\"8142\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662663\" href=\"?#comment-662663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8142\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\">random.johnnyh</a> Can you please elucidate?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662663\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512470\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 08:21\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512470\" href=\"?#comment-512470\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512470\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512470\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have written this O(m*m*n) solution for problem B <a href=\"https://codeforces.com/contest/22/submission/54368605\">https://codeforces.com/contest/22/submission/54368605</a> I am unable to think of any better approach. Can you please provide working code for O(m*n) solution. Thanks in Advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512470 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512470 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512470\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662662\" commentParentId=\"512470\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662662\" href=\"?#comment-662662\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-512470\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662662\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662662\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\">praveenojha33</a> Can you please give a short explanation of your code. Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662662 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662662 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662662\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662743\" commentParentId=\"662662\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 16:15\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662743\" href=\"?#comment-662743\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-662662\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662743\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662743\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Do you know about maximum submatrix sum in a 2D matrix using Kadane Algorithm. If not you can watch it here <a href=\"https://www.youtube.com/watch?v=yCQN096CwWM\">https://www.youtube.com/watch?v=yCQN096CwWM</a></p><p>The problem is same as finding submatrix sum in 2D matrix this can be done using either O(n^4) approach using 2D prefix sum or using Kadane Algorithm in O(n^3). As you know Kadane Algorithm is O(n) and in 2D Kadane Algorithm we divide 2D matrix in n^2 submatrices that is from column (1-1),(1-2),(1-3),(1-4),(2-2),(2-3),(2-4),(3-3),(3-4),(4-4) and then apply kadane Algorithm to find max sum in that rectagular strip. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662743 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662743 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662743\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8061\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ufo008ahw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3037/avatar/99310deaab460f2b.jpg'/> </a>\n <div><a href=\"/profile/ufo008ahw\" title=\"Specialist ufo008ahw\" class=\"rated-user user-cyan\">ufo008ahw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 18:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8061\" href=\"?#comment-8061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3037\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">the complexity of my solution of problem B is O(m^2 * n).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul 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Bargaining Table"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Bargaining Table</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob wants to put a new bargaining table in his office. To do so he measured the office room thoroughly and drew its plan: Bob's office room is a rectangular room <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span> meters. Each square meter of the room is either occupied by some furniture, or free. A bargaining table is rectangular, and should be placed so, that its sides are parallel to the office walls. Bob doesn't want to change or rearrange anything, that's why all the squares that will be occupied by the table should be initially free. Bob wants the new table to sit as many people as possible, thus its perimeter should be maximal. Help Bob find out the maximum possible perimeter of a bargaining table for his office.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains 2 space-separated numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>m</i>โโคโ25</span>) โ the office room dimensions. Then there follow <span class=\"tex-span\"><i>n</i></span> lines with <span class=\"tex-span\"><i>m</i></span> characters 0 or 1 each. 0 stands for a free square meter of the office room. 1 stands for an occupied square meter. It's guaranteed that at least one square meter in the room is free.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output one number โ the maximum possible perimeter of a bargaining table for Bob's office room.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br/>000<br/>010<br/>000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 4<br/>1100<br/>0000<br/>0000<br/>0000<br/>0000<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>16<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"894b5bcb46678f5e8f9a869c0e39ef94\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - B - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"78ba613a0b107244c6d0594b0c9efe02d4e7cf63\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - B - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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To adjust the time limit constraint, a solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then the value 800 ms will be displayed and used to determine the verdict.\r\n </div>\r\n </div>\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:100%;\"><a style=\"color: black\" href=\"/contest/22\">Codeforces Beta Round 22 (Div. 2 Only)</a></th>\n </tr>\n <tr>\n <td class=\"left bottom\" colspan=\"1\"><span class=\"contest-state-phase\">Finished</span></td>\n </tr>\n </tbody>\n </table>\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Practice?\n <div class=\"top-links\">\n </div>\n </div>\n<div>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Want to solve the contest problems after the official contest ends? 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It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/22/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"B\" data-uuid=\"ps_d852e2ba496d5f6bab72ac36e3aba107032093a9\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">B. Bargaining Table</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>2 seconds</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob wants to put a new bargaining table in his office. To do so he measured the office room thoroughly and drew its plan: Bob's office room is a rectangular room <span class=\"tex-span\"><i>n</i>โรโ<i>m</i></span> meters. Each square meter of the room is either occupied by some furniture, or free. A bargaining table is rectangular, and should be placed so, that its sides are parallel to the office walls. Bob doesn't want to change or rearrange anything, that's why all the squares that will be occupied by the table should be initially free. Bob wants the new table to sit as many people as possible, thus its perimeter should be maximal. Help Bob find out the maximum possible perimeter of a bargaining table for his office.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line contains 2 space-separated numbers <span class=\"tex-span\"><i>n</i></span> and <span class=\"tex-span\"><i>m</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>,โ<i>m</i>โโคโ25</span>) โ the office room dimensions. Then there follow <span class=\"tex-span\"><i>n</i></span> lines with <span class=\"tex-span\"><i>m</i></span> characters 0 or 1 each. 0 stands for a free square meter of the office room. 1 stands for an occupied square meter. It's guaranteed that at least one square meter in the room is free.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>Output one number โ the maximum possible perimeter of a bargaining table for Bob's office room.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>3 3<br />000<br />010<br />000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>8<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5 4<br />1100<br />0000<br />0000<br />0000<br />0000<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>16<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=B]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='24bfa389977bffbbea433287f885534f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/iakolzin\">iakolzin</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/iakolzin\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/iakolzin\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/iakolzin\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/iakolzin\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/iakolzin\">Contests</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/iakolzin\" style=\"text-decoration:none;color:black !important;\">iakolzin's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"507\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/507\"> Codeforces Beta Round #22 Tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/iakolzin\" title=\"Master iakolzin\" class=\"rated-user user-orange\">iakolzin</a>,\r\n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"//codeforces.com/blog/entry/505\">Contest discussion</a></p><h3><strong>Problem ะ. Second Order Statistics</strong></h3><p><u>Sorting</u></p><p>In this problem one should find a minimal element from all elements, that are strictly greater, then the minimal one or report that it doesn't exist. Of course, there can be a lot of different solutions, but one of the simplest - to sort the given sequence and print the first element, that's not equal to the previous. If all elements are equal, then the required element doesn't exist.<strong><br /></strong></p><p> </p><h3>Problem B. Bargaining Table</h3><p><u>Simulation, dynamic programming</u></p><p>In this problem one should find the maximal perimeter of a rectangle that contains no '1'. Define these rectangles "correct". To solve a problem you are to check each possible rectangle for correctness and calculate its perimeter. The easiest way to check all rectangles is using 6 nested cycles. Using 4 of them you fix the coordinates while other 2 will look for '1'. So the complexity is O((n*m)<sup>3</sup>). It seems slow, but those, who wrote such a solution, says that it hasn't any problems with TL.<u><br /></u></p><p>One may interest in much faster solution. Using simple DP solution one can get a solution with an O((n*m)<sup>2</sup>) complexity. It's clear, that rectangle with coordinates (x1, y1, x2, y2) is correct if and only if rectangles (x1, y1, x2-1, y2) and (x1, y1, x2, y2-1) are correct, and board[x2][y2] = '0'. So each of rectangles can be checked in O(1) and totally there will be O((n*m)<sup>2</sup>) operations.</p><h3>Problem C. System Administrator</h3><p><u>Simulation</u></p><p>In this problem you are to construct a connected graph, which contains n vertexes and m edges, and if we delete vertex with number v, our graph stops being connected or to report that such a graph doesn't exist. Moreover, each pair of vertexes can have no more than one edge connecting them. Obviously, a connected graph doesn't exist if the number of edges is less than n-1. It's easy to notice, that the maximal possible number of edges reaches when there is a vertex connected to v and doesn't connected to any other vertex, those can form up to complete graph. So the maximal number of edges is (n-1)*(n-2)/2+1. If m is in that range then required graph always exists. Then you should place one vertex on the one side of v (let it be 1), and other vertexes - on the other side. First, you should connect all this vertexes to v and then connect them between each other (except 1).<u><br /></u></p><h3>Problem D. Segments</h3><p><u>Scanning line</u></p><p>In this problem one should place minimal number of points on the line such that any given segment touches at least one of these points. Let's call the coordinate of ending of any segment as event. There will be events of two types: beginning of a segment and its ending. Let's sort this events by coordinates. In the case of equality of some events consider that the event of the beginning will be less than the event of ending. Look at our events from left to right: if there is a beginning event, then push the number of this segment to the special queue. Once we take an ending of some segment, place the point here and clear the special queue (because each of segment in this queue will touch this point).<u><br /></u></p><h3>Problem E. Scheme</h3><p><u>Graph theory</u></p><p>Given an oriented graph, find the minimal number of edges one should add to this graph to make it strongly connected. Looking at statement we can get the fact that each vertex has exactly one outcoming edge. It means that starting at some point we'll get stuck in some cycle. So each connected (not strongly) component is a set of simple paths, ending in some cycle or just a simple cycle. First consider vertexes, which has no incoming edges. When passing through some vertex we'll paint it until the current vertex will be already painted. Then we call the starting vertex as "beginning" and the finishing one as "ending" of a component.<u><br /></u></p><p>After that consider other vertexes - they belong to cycles. Beginning and ending of a cycle - is any vertexes (possible coinciding) belonging to it. So we got a number of components which we have to connect. Let's connect them cyclically: the edge will pass from the ending of i-th component to the beginning of ((i+1)%k)-th, where k is the number of such components. The answer will be k. There is an exception: if we have only one component which is a simple cycle, the answer will be equal to 0.</p><p>So we'll consider each edge exactly once and the total complexity will be O(n).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/22\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 22 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1448-507\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1448\",\n blogEntryId: \"507\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2322\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #22</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+32</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/iakolzin\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/iakolzin\">\n iakolzin\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/507#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/507#comments\">\n 18\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"517\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7927\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/30/2010 22:30\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7927\" href=\"?#comment-7927\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7927\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7927\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Some of your types seem incorrect... Problems B and C are not simulation. Simulation involves running some sort of given process (usually efficiently), and neither of these problems involve that. B is brute force / DP, and C is graph theory.<br /><br />But the tutorial is great, thanks :) I can go fix my E now :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7927 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7927 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7927\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7943\" commentParentId=\"7927\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/yangfan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yangfan\" title=\"Specialist yangfan\" class=\"rated-user user-cyan\">yangfan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 02:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7943\" href=\"?#comment-7943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7927\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4604\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I am not solving E with tutorial's method, and I got Wrong Answer on test 15 for a long time. Did U get any trouble on test 15? Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7956\" commentParentId=\"7943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 07:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7956\" href=\"?#comment-7956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://piratepad.net/ZosxPMMqyK<br /><br />There's my code for it. It passes 15, but gets RE on Test 22. I'm really not sure why. Tell me if you can find it, and hopefully it helps you with yours!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7965\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 12:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7965\" href=\"?#comment-7965\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7965\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7965\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You have stack overflow in dfs. Stack for default thread in java is not very big, you can avoid it by creating your own thread and executing code in it, like<div>class Sample implements Runnable {</div><div><span style=\"white-space: pre;\"> </span>public static void main(String[] args) {</div><div><span style=\"white-space: pre;\"> </span>new Thread(new Sample()).start();</div><div><span style=\"white-space: pre;\"> </span>}</div><div><br /></div><div><span style=\"white-space: pre;\"> </span>public void run() {</div><div><span style=\"white-space: pre;\"> </span>//Solution here</div><div><span style=\"white-space: pre;\"> </span>}</div><div>}</div><div><br /></div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7965 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7965 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7965\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7980\" commentParentId=\"7965\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 20:29\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7980\" href=\"?#comment-7980\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7965\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7980\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7980\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks (to Ivan too)!<br /><br />I really shouldn't have missed that... though I didn't know that a new Thread could get extra stack space. Most interesting.<br /><br />I've got AC now and I've updated my code :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7980 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7980 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7980\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7973\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ivan.popelyshev\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73/avatar/dcae35722510f549.jpg'/> </a>\n <div><a href=\"/profile/ivan.popelyshev\" title=\"Master ivan.popelyshev\" class=\"rated-user user-orange\">ivan.popelyshev</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 16:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7973\" href=\"?#comment-7973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"73\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">new Thread(null, new Sample(), "1", 1<<23).start(); - 8 megabytes stack.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8053\" href=\"?#comment-8053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">problem C may also be solved using a stack + dp, which gives an extremely fast O(mn) solution</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8053\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8054\" commentParentId=\"8053\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8054\" href=\"?#comment-8054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8053\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">*problem B<div><br /></div><div>ps: there really should be an edit function for comments</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8133\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2010 20:03\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8133\" href=\"?#comment-8133\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8133\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8133\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you give more details for the O(mn) solution?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8133 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8133 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8133\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8142\" commentParentId=\"8133\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 00:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8142\" href=\"?#comment-8142\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8133\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8142\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8142\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">its a fairly standard solution<br />its the same as the "largest rectangle in a histogram" problem except now you're looking for maximal perimeter, and you need to do a dp preprocessing<br />the "largest rectangle in a histogram" solution is here: http://homeofcox-cs.blogspot.com/2010/04/max-rectangle-in-histogram-problem.html</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8142 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8142 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8142\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662663\" commentParentId=\"8142\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662663\" href=\"?#comment-662663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8142\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\">random.johnnyh</a> Can you please elucidate?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662663\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512470\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 08:21\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512470\" href=\"?#comment-512470\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512470\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512470\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have written this O(m*m*n) solution for problem B <a href=\"https://codeforces.com/contest/22/submission/54368605\">https://codeforces.com/contest/22/submission/54368605</a> I am unable to think of any better approach. Can you please provide working code for O(m*n) solution. Thanks in Advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512470 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512470 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512470\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662662\" commentParentId=\"512470\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662662\" href=\"?#comment-662662\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-512470\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662662\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662662\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\">praveenojha33</a> Can you please give a short explanation of your code. Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662662 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662662 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662662\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662743\" commentParentId=\"662662\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 16:15\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662743\" href=\"?#comment-662743\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-662662\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662743\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662743\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Do you know about maximum submatrix sum in a 2D matrix using Kadane Algorithm. If not you can watch it here <a href=\"https://www.youtube.com/watch?v=yCQN096CwWM\">https://www.youtube.com/watch?v=yCQN096CwWM</a></p><p>The problem is same as finding submatrix sum in 2D matrix this can be done using either O(n^4) approach using 2D prefix sum or using Kadane Algorithm in O(n^3). As you know Kadane Algorithm is O(n) and in 2D Kadane Algorithm we divide 2D matrix in n^2 submatrices that is from column (1-1),(1-2),(1-3),(1-4),(2-2),(2-3),(2-4),(3-3),(3-4),(4-4) and then apply kadane Algorithm to find max sum in that rectagular strip. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662743 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662743 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662743\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8061\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ufo008ahw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3037/avatar/99310deaab460f2b.jpg'/> </a>\n <div><a href=\"/profile/ufo008ahw\" title=\"Specialist ufo008ahw\" class=\"rated-user user-cyan\">ufo008ahw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 18:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8061\" href=\"?#comment-8061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3037\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">the complexity of my solution of problem B is O(m^2 * n).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul 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System Administrator"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">C. System Administrator</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob got a job as a system administrator in X corporation. His first task was to connect <span class=\"tex-span\"><i>n</i></span> servers with the help of <span class=\"tex-span\"><i>m</i></span> two-way direct connection so that it becomes possible to transmit data from one server to any other server via these connections. Each direct connection has to link two different servers, each pair of servers should have at most one direct connection. Y corporation, a business rival of X corporation, made Bob an offer that he couldn't refuse: Bob was asked to connect the servers in such a way, that when server with index <span class=\"tex-span\"><i>v</i></span> fails, the transmission of data between some other two servers becomes impossible, i.e. the system stops being connected. Help Bob connect the servers.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 3 space-separated integer numbers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>v</i></span> (<span class=\"tex-span\">3โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup>,โ0โโคโ<i>m</i>โโคโ10<sup class=\"upper-index\">5</sup>,โ1โโคโ<i>v</i>โโคโ<i>n</i></span>), <span class=\"tex-span\"><i>n</i></span> โ amount of servers, <span class=\"tex-span\"><i>m</i></span> โ amount of direct connections, <span class=\"tex-span\"><i>v</i></span> โ index of the server that fails and leads to the failure of the whole system.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If it is impossible to connect the servers in the required way, output <span class=\"tex-font-style-tt\">-1</span>. Otherwise output <span class=\"tex-span\"><i>m</i></span> lines with 2 numbers each โ description of all the direct connections in the system. Each direct connection is described by two numbers โ indexes of two servers, linked by this direct connection. The servers are numbered from 1. If the answer is not unique, output any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 6 3<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 2<br/>2 3<br/>3 4<br/>4 5<br/>1 3<br/>3 5<br/></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 100 1<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"09e227c2b315b524d03167adf1d37c65\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - C - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"78ba613a0b107244c6d0594b0c9efe02d4e7cf63\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - C - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='09e227c2b315b524d03167adf1d37c65'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/22/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = $(this).hasClass(\"la-angle-right\");\r\n const params = {\r\n action: \"setCollapsed\",\r\n sidebarFrameSimpleClassName: \"ContestVirtualFrame\",\r\n collapsed\r\n };\r\n $.each($target[0].attributes, function(i, a) {\r\n const name = a.name;\r\n if (name.startsWith(\"data-extra-key-\")) {\r\n const key = a.value;\r\n const keyIndex = parseInt(name.substring(\"data-extra-key-\".length));\r\n const value = $target.attr(\"data-extra-value-\" + keyIndex);\r\n params[key] = value;\r\n }\r\n });\r\n $.post(dataPageUrl, params, function (result) {\r\n if (result[\"success\"] !== \"true\") {\r\n Codeforces.showMessage(\"Failed to save collapsed state.\");\r\n }\r\n }, \"json\");\r\n return false;\r\n });\r\n })\r\n </script>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Problem tags\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\"padding: 0.5em;\">\r\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Graphs\">\r\n graphs\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1700\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='09e227c2b315b524d03167adf1d37c65'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"101\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='09e227c2b315b524d03167adf1d37c65'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"101\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, function () {\r\n }, \"Yes\", \"No\");\r\n });\r\n\r\n $(\"#addTagLink\").click(function () {\r\n $(this).hide();\r\n $(\"#addTagLabel\").show();\r\n return false;\r\n });\r\n\r\n $(\"#addTagSelect\").change(function () {\r\n var tagName = $(this).val();\r\n if (tagName === \"\") 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title=\"Codeforces Beta Round #22 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"109:110\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/507\" title=\"Codeforces Beta Round #22 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"459:460\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" 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class=\"header\"><div class=\"title\">C. System Administrator</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>Bob got a job as a system administrator in X corporation. His first task was to connect <span class=\"tex-span\"><i>n</i></span> servers with the help of <span class=\"tex-span\"><i>m</i></span> two-way direct connection so that it becomes possible to transmit data from one server to any other server via these connections. Each direct connection has to link two different servers, each pair of servers should have at most one direct connection. Y corporation, a business rival of X corporation, made Bob an offer that he couldn't refuse: Bob was asked to connect the servers in such a way, that when server with index <span class=\"tex-span\"><i>v</i></span> fails, the transmission of data between some other two servers becomes impossible, i.e. the system stops being connected. Help Bob connect the servers.</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first input line contains 3 space-separated integer numbers <span class=\"tex-span\"><i>n</i></span>, <span class=\"tex-span\"><i>m</i></span>, <span class=\"tex-span\"><i>v</i></span> (<span class=\"tex-span\">3โโคโ<i>n</i>โโคโ10<sup class=\"upper-index\">5</sup>,โ0โโคโ<i>m</i>โโคโ10<sup class=\"upper-index\">5</sup>,โ1โโคโ<i>v</i>โโคโ<i>n</i></span>), <span class=\"tex-span\"><i>n</i></span> โ amount of servers, <span class=\"tex-span\"><i>m</i></span> โ amount of direct connections, <span class=\"tex-span\"><i>v</i></span> โ index of the server that fails and leads to the failure of the whole system.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>If it is impossible to connect the servers in the required way, output <span class=\"tex-font-style-tt\">-1</span>. Otherwise output <span class=\"tex-span\"><i>m</i></span> lines with 2 numbers each โ description of all the direct connections in the system. Each direct connection is described by two numbers โ indexes of two servers, linked by this direct connection. The servers are numbered from 1. If the answer is not unique, output any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>5 6 3<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1 2<br />2 3<br />3 4<br />4 5<br />1 3<br />3 5<br /></pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>6 100 1<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>-1<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=C]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n 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dark\"><a href=\"/profile/orzdevinwang\" title=\"Legendary Grandmaster orzdevinwang\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">o</span>rzdevinwang</a></td>\n<td class=\" dark\">3697</td>\n</tr>\n<tr>\n<td class=\"left \">4</td>\n<td class=\"\"><a href=\"/profile/Radewoosh\" title=\"Legendary Grandmaster Radewoosh\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>adewoosh</a></td>\n<td class=\"\">3651</td>\n</tr>\n<tr>\n<td class=\"left dark\">5</td>\n<td class=\" dark\"><a href=\"/profile/jiangly\" title=\"Legendary Grandmaster jiangly\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">j</span>iangly</a></td>\n<td class=\" dark\">3632</td>\n</tr>\n<tr>\n<td class=\"left \">6</td>\n<td class=\"\"><a href=\"/profile/cnnfls_csy\" title=\"Legendary Grandmaster cnnfls_csy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='24bfa389977bffbbea433287f885534f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/iakolzin\">iakolzin</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/iakolzin\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/iakolzin\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/iakolzin\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/iakolzin\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/iakolzin\">Contests</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/iakolzin\" style=\"text-decoration:none;color:black !important;\">iakolzin's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"507\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/507\"> Codeforces Beta Round #22 Tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/iakolzin\" title=\"Master iakolzin\" class=\"rated-user user-orange\">iakolzin</a>,\r\n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"//codeforces.com/blog/entry/505\">Contest discussion</a></p><h3><strong>Problem ะ. Second Order Statistics</strong></h3><p><u>Sorting</u></p><p>In this problem one should find a minimal element from all elements, that are strictly greater, then the minimal one or report that it doesn't exist. Of course, there can be a lot of different solutions, but one of the simplest - to sort the given sequence and print the first element, that's not equal to the previous. If all elements are equal, then the required element doesn't exist.<strong><br /></strong></p><p> </p><h3>Problem B. Bargaining Table</h3><p><u>Simulation, dynamic programming</u></p><p>In this problem one should find the maximal perimeter of a rectangle that contains no '1'. Define these rectangles "correct". To solve a problem you are to check each possible rectangle for correctness and calculate its perimeter. The easiest way to check all rectangles is using 6 nested cycles. Using 4 of them you fix the coordinates while other 2 will look for '1'. So the complexity is O((n*m)<sup>3</sup>). It seems slow, but those, who wrote such a solution, says that it hasn't any problems with TL.<u><br /></u></p><p>One may interest in much faster solution. Using simple DP solution one can get a solution with an O((n*m)<sup>2</sup>) complexity. It's clear, that rectangle with coordinates (x1, y1, x2, y2) is correct if and only if rectangles (x1, y1, x2-1, y2) and (x1, y1, x2, y2-1) are correct, and board[x2][y2] = '0'. So each of rectangles can be checked in O(1) and totally there will be O((n*m)<sup>2</sup>) operations.</p><h3>Problem C. System Administrator</h3><p><u>Simulation</u></p><p>In this problem you are to construct a connected graph, which contains n vertexes and m edges, and if we delete vertex with number v, our graph stops being connected or to report that such a graph doesn't exist. Moreover, each pair of vertexes can have no more than one edge connecting them. Obviously, a connected graph doesn't exist if the number of edges is less than n-1. It's easy to notice, that the maximal possible number of edges reaches when there is a vertex connected to v and doesn't connected to any other vertex, those can form up to complete graph. So the maximal number of edges is (n-1)*(n-2)/2+1. If m is in that range then required graph always exists. Then you should place one vertex on the one side of v (let it be 1), and other vertexes - on the other side. First, you should connect all this vertexes to v and then connect them between each other (except 1).<u><br /></u></p><h3>Problem D. Segments</h3><p><u>Scanning line</u></p><p>In this problem one should place minimal number of points on the line such that any given segment touches at least one of these points. Let's call the coordinate of ending of any segment as event. There will be events of two types: beginning of a segment and its ending. Let's sort this events by coordinates. In the case of equality of some events consider that the event of the beginning will be less than the event of ending. Look at our events from left to right: if there is a beginning event, then push the number of this segment to the special queue. Once we take an ending of some segment, place the point here and clear the special queue (because each of segment in this queue will touch this point).<u><br /></u></p><h3>Problem E. Scheme</h3><p><u>Graph theory</u></p><p>Given an oriented graph, find the minimal number of edges one should add to this graph to make it strongly connected. Looking at statement we can get the fact that each vertex has exactly one outcoming edge. It means that starting at some point we'll get stuck in some cycle. So each connected (not strongly) component is a set of simple paths, ending in some cycle or just a simple cycle. First consider vertexes, which has no incoming edges. When passing through some vertex we'll paint it until the current vertex will be already painted. Then we call the starting vertex as "beginning" and the finishing one as "ending" of a component.<u><br /></u></p><p>After that consider other vertexes - they belong to cycles. Beginning and ending of a cycle - is any vertexes (possible coinciding) belonging to it. So we got a number of components which we have to connect. Let's connect them cyclically: the edge will pass from the ending of i-th component to the beginning of ((i+1)%k)-th, where k is the number of such components. The answer will be k. There is an exception: if we have only one component which is a simple cycle, the answer will be equal to 0.</p><p>So we'll consider each edge exactly once and the total complexity will be O(n).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/22\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 22 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1448-507\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1448\",\n blogEntryId: \"507\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2322\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #22</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+32</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/iakolzin\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/iakolzin\">\n iakolzin\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/507#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/507#comments\">\n 18\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"517\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7927\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/30/2010 22:30\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7927\" href=\"?#comment-7927\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7927\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7927\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Some of your types seem incorrect... Problems B and C are not simulation. Simulation involves running some sort of given process (usually efficiently), and neither of these problems involve that. B is brute force / DP, and C is graph theory.<br /><br />But the tutorial is great, thanks :) I can go fix my E now :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7927 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7927 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7927\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7943\" commentParentId=\"7927\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/yangfan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yangfan\" title=\"Specialist yangfan\" class=\"rated-user user-cyan\">yangfan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 02:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7943\" href=\"?#comment-7943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7927\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4604\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I am not solving E with tutorial's method, and I got Wrong Answer on test 15 for a long time. Did U get any trouble on test 15? Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7956\" commentParentId=\"7943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 07:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7956\" href=\"?#comment-7956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://piratepad.net/ZosxPMMqyK<br /><br />There's my code for it. It passes 15, but gets RE on Test 22. I'm really not sure why. Tell me if you can find it, and hopefully it helps you with yours!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7965\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 12:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7965\" href=\"?#comment-7965\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7965\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7965\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You have stack overflow in dfs. Stack for default thread in java is not very big, you can avoid it by creating your own thread and executing code in it, like<div>class Sample implements Runnable {</div><div><span style=\"white-space: pre;\"> </span>public static void main(String[] args) {</div><div><span style=\"white-space: pre;\"> </span>new Thread(new Sample()).start();</div><div><span style=\"white-space: pre;\"> </span>}</div><div><br /></div><div><span style=\"white-space: pre;\"> </span>public void run() {</div><div><span style=\"white-space: pre;\"> </span>//Solution here</div><div><span style=\"white-space: pre;\"> </span>}</div><div>}</div><div><br /></div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7965 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7965 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7965\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7980\" commentParentId=\"7965\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 20:29\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7980\" href=\"?#comment-7980\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7965\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7980\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7980\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks (to Ivan too)!<br /><br />I really shouldn't have missed that... though I didn't know that a new Thread could get extra stack space. Most interesting.<br /><br />I've got AC now and I've updated my code :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7980 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7980 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7980\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7973\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ivan.popelyshev\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73/avatar/dcae35722510f549.jpg'/> </a>\n <div><a href=\"/profile/ivan.popelyshev\" title=\"Master ivan.popelyshev\" class=\"rated-user user-orange\">ivan.popelyshev</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 16:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7973\" href=\"?#comment-7973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"73\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">new Thread(null, new Sample(), "1", 1<<23).start(); - 8 megabytes stack.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8053\" href=\"?#comment-8053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">problem C may also be solved using a stack + dp, which gives an extremely fast O(mn) solution</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8053\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8054\" commentParentId=\"8053\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8054\" href=\"?#comment-8054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8053\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">*problem B<div><br /></div><div>ps: there really should be an edit function for comments</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8133\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2010 20:03\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8133\" href=\"?#comment-8133\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8133\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8133\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you give more details for the O(mn) solution?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8133 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8133 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8133\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8142\" commentParentId=\"8133\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 00:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8142\" href=\"?#comment-8142\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8133\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8142\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8142\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">its a fairly standard solution<br />its the same as the "largest rectangle in a histogram" problem except now you're looking for maximal perimeter, and you need to do a dp preprocessing<br />the "largest rectangle in a histogram" solution is here: http://homeofcox-cs.blogspot.com/2010/04/max-rectangle-in-histogram-problem.html</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8142 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8142 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8142\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662663\" commentParentId=\"8142\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662663\" href=\"?#comment-662663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8142\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\">random.johnnyh</a> Can you please elucidate?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662663\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512470\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 08:21\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512470\" href=\"?#comment-512470\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512470\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512470\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have written this O(m*m*n) solution for problem B <a href=\"https://codeforces.com/contest/22/submission/54368605\">https://codeforces.com/contest/22/submission/54368605</a> I am unable to think of any better approach. Can you please provide working code for O(m*n) solution. Thanks in Advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512470 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512470 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512470\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662662\" commentParentId=\"512470\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662662\" href=\"?#comment-662662\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-512470\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662662\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662662\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\">praveenojha33</a> Can you please give a short explanation of your code. Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662662 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662662 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662662\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662743\" commentParentId=\"662662\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 16:15\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662743\" href=\"?#comment-662743\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-662662\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662743\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662743\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Do you know about maximum submatrix sum in a 2D matrix using Kadane Algorithm. If not you can watch it here <a href=\"https://www.youtube.com/watch?v=yCQN096CwWM\">https://www.youtube.com/watch?v=yCQN096CwWM</a></p><p>The problem is same as finding submatrix sum in 2D matrix this can be done using either O(n^4) approach using 2D prefix sum or using Kadane Algorithm in O(n^3). As you know Kadane Algorithm is O(n) and in 2D Kadane Algorithm we divide 2D matrix in n^2 submatrices that is from column (1-1),(1-2),(1-3),(1-4),(2-2),(2-3),(2-4),(3-3),(3-4),(4-4) and then apply kadane Algorithm to find max sum in that rectagular strip. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662743 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662743 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662743\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8061\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ufo008ahw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3037/avatar/99310deaab460f2b.jpg'/> </a>\n <div><a href=\"/profile/ufo008ahw\" title=\"Specialist ufo008ahw\" class=\"rated-user user-cyan\">ufo008ahw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 18:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8061\" href=\"?#comment-8061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3037\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">the complexity of my solution of problem B is O(m^2 * n).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul 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Segments"},"problem_statement":{"kind":"string","value":"<div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Segments</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given <span class=\"tex-span\"><i>n</i></span> segments on the Ox-axis. You can drive a nail in any integer point on the Ox-axis line nail so, that all segments containing this point, are considered nailed down. If the nail passes through endpoint of some segment, this segment is considered to be nailed too. What is the smallest number of nails needed to nail all the segments down?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains single integer number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ1000</span>) โ amount of segments. Following <span class=\"tex-span\"><i>n</i></span> lines contain descriptions of the segments. Each description is a pair of integer numbers โ endpoints coordinates. All the coordinates don't exceed 10000 by absolute value. Segments can degenarate to points.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>The first line should contain one integer number โ the smallest number of nails needed to nail all the segments down. The second line should contain coordinates of driven nails separated by space in any order. If the answer is not unique, output any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br/>0 2<br/>2 5<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br/>2 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br/>0 3<br/>4 2<br/>4 8<br/>8 10<br/>7 7<br/></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br/>7 10 3<br/></pre></div></div></div></div>"},"page":{"kind":"string","value":"\r\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n<html lang=\"en\">\n<head>\n <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">\n <meta name=\"X-Csrf-Token\" content=\"24180175d2452780123da73242a5c588\"/>\n <meta id=\"viewport\" name=\"viewport\" content=\"width=device-width, initial-scale=0.01\"/>\n\n\n <script type=\"text/javascript\" src=\"//codeforces.org/s/73366/js/jquery-1.8.3.js\"></script>\n <script type=\"application/javascript\">\n window.locale = \"en\";\n window.standaloneContest = false;\n function adjustViewport() {\n var screenWidthPx = Math.min($(window).width(), window.screen.width);\n var siteWidthPx = 1100; // min width of site\n var ratio = Math.min(screenWidthPx / siteWidthPx, 1.0);\n var viewport = \"width=device-width, initial-scale=\" + ratio;\n $('#viewport').attr('content', viewport);\n var style = $('<style>html * { max-height: 1000000px; }</style>');\n $('html > head').append(style);\n }\n\n if ( /Android|webOS|iPhone|iPad|iPod|BlackBerry/i.test(navigator.userAgent) ) {\n adjustViewport();\n }\n\n /* Protection against trailing dot in domain. */\n let hostLength = window.location.host.length;\n if (hostLength > 1 && window.location.host[hostLength - 1] === '.') {\n window.location = window.location.protocol + \"//\" + window.location.host.substring(0, hostLength - 1);\n }\n </script>\n <meta http-equiv=\"pragma\" content=\"no-cache\">\n <meta http-equiv=\"expires\" content=\"-1\">\n <meta http-equiv=\"profileName\" content=\"j3\">\n <meta name=\"google-site-verification\" content=\"OTd2dN5x4nS4OPknPI9JFg36fKxjqY0i1PSfFPv_J90\"/>\n <meta property=\"fb:admins\" content=\"100001352546622\" />\n <meta property=\"og:image\" content=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <link rel=\"image_src\" href=\"//codeforces.org/s/73366/images/codeforces-sponsored-by-ton.png\" />\n <meta property=\"og:title\" content=\"Problem - D - Codeforces\"/>\n <meta property=\"og:description\" content=\"\"/>\n \n <meta property=\"og:site_name\" content=\"Codeforces\"/>\n \n \n \n <meta name=\"cc\" content=\"78ba613a0b107244c6d0594b0c9efe02d4e7cf63\"/>\n \n \n <meta name=\"utc_offset\" content=\"+03:00\"/>\n <meta name=\"verify-reformal\" content=\"f56f99fd7e087fb6ccb48ef2\" />\n <title>Problem - D - Codeforces</title>\n <meta name=\"description\" content=\"Codeforces. 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Just register for practice and you will be able to submit solutions.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"\" method=\"post\"><input type='hidden' name='csrf_token' value='24180175d2452780123da73242a5c588'/>\r\n <input type=\"hidden\" name=\"action\" value=\"registerForPractice\"/>\r\n <input type=\"submit\" name=\"submit\" value=\"Register for practice\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div> \r\n</div>\r\n </div>\n\r\n\r\n\n <div class=\"roundbox sidebox ContestVirtualFrame borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Virtual participation <i class=\"sidebar-caption-icon las la-angle-down\"></i>\r\n\n <div class=\"top-links\">\n </div>\n </div>\n<div style=\" \"\r\n\r\n data-page-url=\"/data/sidebarFrames\"\r\n\r\n>\r\n <div style=\"margin:1em;font-size:0.8em;\">\r\n Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.\n\nIf you've seen these problems, a virtual contest is not for you - solve these problems in the archive.\n\nIf you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.\n\nNever use someone else's code, read the tutorials or communicate with other person during a virtual contest.\r\n </div>\r\n\r\n <div style=\"text-align:center;margin:1em;\">\r\n <form action=\"/contest/22/virtual\" method=\"get\">\r\n <input type=\"submit\" name=\"submit\" value=\"Start virtual contest\" style=\"padding:0 0.5em;\">\r\n </form>\r\n </div>\r\n</div>\r\n <script>\r\n $(function () {\r\n $(\".ContestVirtualFrame .sidebar-caption-icon\").click(function() {\r\n $(this).toggleClass(\"la-angle-down la-angle-right\");\r\n const $target = $(this).parent().next();\r\n $target.toggle();\r\n const dataPageUrl = $target.attr(\"data-page-url\");\r\n const collapsed = 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style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Greedy algorithms\">\r\n greedy\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Sortings, orderings\">\r\n sortings\r\n</span>\r\n </div>\n\n <div class=\"roundbox borderTopRound borderBottomRound\" style=\"margin:2px; padding:0 3px 2px 3px; background-color:#f0f0f0;float:left;\">\n<span class=\"tag-box\" style=\"font-size:1.2rem;\" title=\"Difficulty\">\r\n *1900\r\n</span>\r\n </div>\n <div style=\"clear:both;text-align:right;font-size:1.1rem;\">\r\n <span title=\"Please login into the Codeforces\" class=\"notice\">No tag edit access</span>\r\n </div>\r\n</div>\r\n </div>\n\r\n<form id=\"addTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='24180175d2452780123da73242a5c588'/>\r\n <input name=\"action\" type=\"hidden\" value=\"addTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"102\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<form id=\"removeTagForm\" action=\"/data/problemTags\" method=\"post\" style=\"display:none;\"><input type='hidden' name='csrf_token' value='24180175d2452780123da73242a5c588'/>\r\n <input name=\"action\" type=\"hidden\" value=\"removeTag\"/>\r\n <input name=\"problemId\" type=\"hidden\" value=\"102\"/>\r\n <input name=\"tagName\" type=\"hidden\" value=\"\"/>\r\n</form>\r\n\r\n<script type=\"text/javascript\">\r\n $(\".tag-box img\").click(function () {\r\n var tagName = $(this).attr(\"value\");\r\n Codeforces.confirm(\"Are you sure you want to remove this tag?\", function () {\r\n $(\"#removeTagForm input[name=tagName]\").val(tagName);\r\n $(\"#removeTagForm\").submit();\r\n }, 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Monaco, \"Courier New\", Courier, monospace;\r\n}\r\n</style>\r\n<div class=\"roundbox sidebox sidebar-menu borderTopRound \" style=\"\">\n<div class=\"caption titled\">→ Contest materials\n<div class=\"top-links\">\n</div>\n</div>\n<ul>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/505\" title=\"Codeforces Beta Round #22 (Div. 2)\" target=\"_blank\">Announcement</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"109:110\" resourceName=\"Announcement\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n<li>\r\n<span>\r\n<a href=\"/blog/entry/507\" title=\"Codeforces Beta Round #22 Tutorial\" target=\"_blank\">Tutorial</a>\r\n</span>\r\n<span style=\"float: right;\">\r\n<img class=\"delete-resource-link\" resourceIds=\"459:460\" resourceName=\"Tutorial\"\r\nresourceManual=\"true\" src=\"//codeforces.org/s/73366/images/icons/close-10x10.png\"\r\nstyle=\"position: relative;bottom: -1px;left: 1px;cursor: pointer;\"/>\r\n</span>\r\n<div style=\"clear: both;\"></div>\r\n</li>\r\n</ul>\r\n</div></div>\n <div id=\"pageContent\" class=\"content-with-sidebar\">\n <div class=\"second-level-menu\">\r\n<ul class=\"second-level-menu-list\">\r\n <li class=\"current selectedLava\"><a\r\n href=\"/contest/22\">Problems</a></li>\r\n <li><a\r\n href=\"/contest/22/submit\">Submit Code</a></li>\r\n <li><a\r\n href=\"/contest/22/my\">My Submissions</a></li>\r\n <li><a\r\n href=\"/contest/22/status\">Status</a></li>\r\n <li><a\r\n href=\"/contest/22/standings\">Standings</a></li>\r\n <li><a\r\n href=\"/contest/22/customtest\">Custom Invocation</a></li>\r\n</ul>\r\n</div>\n\r\n <style>\r\n #facebox .content:has(.diff-popup) {\r\n width: 90vw;\r\n max-width: 120rem !important;\r\n }\r\n\r\n .testCaseMarker {\r\n position: 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convertStatementToText = function(statmentNode) {\r\n const text = nodeToText(statmentNode, false).join(\"\").replace(/ +/g, \" \").replace(/\\n\\n+/g, \"\\n\\n\");\r\n let result = [];\r\n for (let i = 0; i < text.length; i++) {\r\n const c = text.charAt(i);\r\n if (c === OPENING_SPACE) {\r\n if (!((i > 0 && text.charAt(i - 1) === '(') || (result.length > 0 && result[result.length - 1] === ' '))) {\r\n result.push('+');\r\n }\r\n } else if (c === CLOSING_SPACE) {\r\n if (!(i + 1 < text.length && isSpecial(text.charAt(i + 1)))) {\r\n result.push('-');\r\n }\r\n } else {\r\n result.push(c);\r\n }\r\n }\r\n return result.join(\"\").split(\"\\n\").map(value => value.trim()).join(\"\\n\");\r\n };\r\n </script>\r\n <div class=\"diff-popup\">\r\n </div>\r\n\r\n<div class=\"problemindexholder\" problemindex=\"D\" data-uuid=\"ps_21143fa413b8509bf0cbee6d284345a55949e23c\">\r\n <div style=\"display: none; margin:1em 0;text-align: center; position: relative;\" class=\"alert alert-info diff-notifier\">\r\n <div>The problem statement has recently been changed. <a class=\"view-changes\" href=\"#\">View the changes.</a></div>\r\n <span class=\"diff-notifier-close\" style=\"position: absolute; top: 0.2em; right: 0.3em; cursor: pointer; font-size: 1.4em;\">×</span>\r\n </div>\r\n <div class=\"ttypography\"><div class=\"problem-statement\"><div class=\"header\"><div class=\"title\">D. Segments</div><div class=\"time-limit\"><div class=\"property-title\">time limit per test</div>1 second</div><div class=\"memory-limit\"><div class=\"property-title\">memory limit per test</div>256 megabytes</div><div class=\"input-file\"><div class=\"property-title\">input</div>standard input</div><div class=\"output-file\"><div class=\"property-title\">output</div>standard output</div></div><div><p>You are given <span class=\"tex-span\"><i>n</i></span> segments on the Ox-axis. You can drive a nail in any integer point on the Ox-axis line nail so, that all segments containing this point, are considered nailed down. If the nail passes through endpoint of some segment, this segment is considered to be nailed too. What is the smallest number of nails needed to nail all the segments down?</p></div><div class=\"input-specification\"><div class=\"section-title\">Input</div><p>The first line of the input contains single integer number <span class=\"tex-span\"><i>n</i></span> (<span class=\"tex-span\">1โโคโ<i>n</i>โโคโ1000</span>) โ amount of segments. Following <span class=\"tex-span\"><i>n</i></span> lines contain descriptions of the segments. Each description is a pair of integer numbers โ endpoints coordinates. All the coordinates don't exceed 10000 by absolute value. Segments can degenarate to points.</p></div><div class=\"output-specification\"><div class=\"section-title\">Output</div><p>The first line should contain one integer number โ the smallest number of nails needed to nail all the segments down. The second line should contain coordinates of driven nails separated by space in any order. If the answer is not unique, output any.</p></div><div class=\"sample-tests\"><div class=\"section-title\">Examples</div><div class=\"sample-test\"><div class=\"input\"><div class=\"title\">Input</div><pre>2<br />0 2<br />2 5<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>1<br />2 </pre></div><div class=\"input\"><div class=\"title\">Input</div><pre>5<br />0 3<br />4 2<br />4 8<br />8 10<br />7 7<br /></pre></div><div class=\"output\"><div class=\"title\">Output</div><pre>3<br />7 10 3<br /></pre></div></div></div></div></div>\r\n</div>\r\n\r\n <script>\r\n $(function () {\r\n Codeforces.addMathJaxListener(function () {\r\n let $problem = $(\"div[problemindex=D]\");\r\n let uuid = $problem.attr(\"data-uuid\");\r\n let statementText = convertStatementToText($problem.find(\".ttypography\").get(0));\r\n\r\n let previousStatementText = Codeforces.getFromStorage(uuid);\r\n if (previousStatementText) {\r\n if (previousStatementText !== statementText) {\r\n 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class=\"legendary-user-first-letter\">c</span>nnfls_csy</a></td>\n<td class=\"\">3620</td>\n</tr>\n<tr>\n<td class=\"left dark\">7</td>\n<td class=\" dark\"><a href=\"/profile/-0.5\" title=\"Legendary Grandmaster -0.5\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">-</span>0.5</a></td>\n<td class=\" dark\">3545</td>\n</tr>\n<tr>\n<td class=\"left \">8</td>\n<td class=\"\"><a href=\"/profile/inaFSTream\" title=\"Legendary Grandmaster inaFSTream\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">i</span>naFSTream</a></td>\n<td class=\"\">3478</td>\n</tr>\n<tr>\n<td class=\"left dark\">9</td>\n<td class=\" dark\"><a href=\"/profile/fantasy\" title=\"Legendary Grandmaster fantasy\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">f</span>antasy</a></td>\n<td class=\" dark\">3468</td>\n</tr>\n<tr>\n<td class=\"left bottom\">10</td>\n<td class=\"bottom\"><a href=\"/profile/Rebelz\" title=\"Legendary Grandmaster Rebelz\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">R</span>ebelz</a></td>\n<td class=\"bottom\">3415</td>\n</tr>\n</tbody>\n</table>\n<div class=\"bottom-links\">\n<table style=\"width:100%;\">\n<tbody>\n<tr>\n<td style=\"text-align:left;\">\n<a href=\"/ratings/countries\">Countries</a> |\n<a href=\"/ratings/cities\">Cities</a> |\n<a href=\"/ratings/organizations\">Organizations</a>\n</td>\n<td style=\"text-align:right;\">\n<a href=\"/ratings\">View all →</a>\n</td>\n</tr>\n</tbody>\n</table>\n</div>\n</div><div class=\"roundbox sidebox top-contributed borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Top contributors\n <div class=\"top-links\">\n </div>\n </div>\n <table class=\"rtable \">\n <tbody>\n <tr>\n <th class=\"left\" style=\"width:2.25em;\">#</th>\n <th class=\"\">User</th>\n <th class=\"\" style=\"width:5em;\">Contrib.</th>\n </tr>\n <tr>\n <td class=\"left dark\">1</td>\n <td class=\" dark\"><a href=\"/profile/adamant\" title=\"Grandmaster adamant\" class=\"rated-user user-red\">adamant</a></td>\n <td class=\" dark\">178</td>\n </tr>\n <tr>\n <td class=\"left \">2</td>\n <td class=\"\"><a href=\"/profile/awoo\" title=\"Master awoo\" class=\"rated-user user-orange\">awoo</a></td>\n <td class=\"\">167</td>\n </tr>\n <tr>\n <td class=\"left dark\">3</td>\n <td class=\" dark\"><a href=\"/profile/BledDest\" title=\"International Grandmaster BledDest\" class=\"rated-user user-red\">BledDest</a></td>\n <td class=\" dark\">165</td>\n </tr>\n <tr>\n <td class=\"left \">4</td>\n <td class=\"\"><a href=\"/profile/Um_nik\" title=\"Legendary Grandmaster Um_nik\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">U</span>m_nik</a></td>\n <td class=\"\">163</td>\n </tr>\n <tr>\n <td class=\"left dark\">5</td>\n <td class=\" dark\"><a href=\"/profile/maroonrk\" title=\"Legendary Grandmaster maroonrk\" class=\"rated-user user-legendary\"><span class=\"legendary-user-first-letter\">m</span>aroonrk</a></td>\n <td class=\" dark\">162</td>\n </tr>\n <tr>\n <td class=\"left \">6</td>\n <td class=\"\"><a href=\"/profile/SecondThread\" title=\"Master SecondThread\" class=\"rated-user user-orange\">SecondThread</a></td>\n <td class=\"\">160</td>\n </tr>\n <tr>\n <td class=\"left dark\">7</td>\n <td class=\" dark\"><a href=\"/profile/nor\" title=\"Master nor\" class=\"rated-user user-orange\">nor</a></td>\n <td class=\" dark\">158</td>\n </tr>\n <tr>\n <td class=\"left \">8</td>\n <td class=\"\"><a href=\"/profile/-is-this-fft-\" title=\"Grandmaster -is-this-fft-\" class=\"rated-user user-red\">-is-this-fft-</a></td>\n <td class=\"\">152</td>\n </tr>\n <tr>\n <td class=\"left dark\">9</td>\n <td class=\" dark\"><a href=\"/profile/kostka\" title=\"International Grandmaster kostka\" class=\"rated-user user-red\">kostka</a></td>\n <td class=\" dark\">145</td>\n </tr>\n <tr>\n <td class=\"left bottom\">10</td>\n <td class=\"bottom\"><a href=\"/profile/TheScrasse\" title=\"International Grandmaster TheScrasse\" class=\"rated-user user-red\">TheScrasse</a></td>\n <td class=\"bottom\">144</td>\n </tr>\n </tbody>\n </table>\n <div class=\"bottom-links\">\n <table style=\"width:100%;\">\n <tbody>\n <tr>\n <td style=\"text-align:left;\">\n </td>\n <td style=\"text-align:right;\">\n <a href=\"/top-contributed\">View all →</a>\n </td>\n </tr>\n </tbody>\n </table>\n </div>\n </div>\n\r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n });\n </script>\r\n\r\n\n <div class=\"roundbox sidebox borderTopRound \" style=\"\">\n <div class=\"caption titled\">→ Find user\n <div class=\"top-links\">\n </div>\n </div>\n <form class=\"handleForm\" method=\"post\"><input type='hidden' name='csrf_token' value='24bfa389977bffbbea433287f885534f'/>\r\n <div style=\"padding:1em;text-align:right;\">\r\n <label style=\"padding-right:1em;\">Handle:\r\n <input style=\"width:12em;\" type=\"text\" class=\"handleBox\"/>\r\n 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href=\"/profile/iakolzin\">iakolzin</a></li>\r\n <li class=\"current selectedLava\"><a\r\n href=\"/blog/iakolzin\">Blog</a></li>\r\n <li><a\r\n href=\"/teams/with/iakolzin\">Teams</a></li>\r\n <li><a\r\n href=\"/submissions/iakolzin\">Submissions</a></li>\r\n <li><a\r\n href=\"/groups/with/iakolzin\">Groups</a></li>\r\n <li><a\r\n href=\"/contests/with/iakolzin\">Contests</a></li>\r\n</ul>\r\n</div>\n <div style=\"margin-top:0;\">\r\n <div>\r\n <h3><a href=\"/blog/iakolzin\" style=\"text-decoration:none;color:black !important;\">iakolzin's blog</a></h3>\r\n </div>\r\n <div style=\"margin-top:2em;\">\r\n\r\n\r\n<div class=\"has-topic-id topic\" topicId=\"507\">\r\n <div class=\"title\">\r\n <a href=\"/blog/entry/507\"> Codeforces Beta Round #22 Tutorial\r\n</a>\r\n </div>\r\n\r\n <div class=\"info\" style=\"position:relative;\">\r\n By <a href=\"/profile/iakolzin\" title=\"Master iakolzin\" class=\"rated-user user-orange\">iakolzin</a>,\r\n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>,\r\n translation,\r\n <img style=\"position: relative;top: 5px;\" src=\"//codeforces.org/s/81027/images/flags/24/gb.png\" alt=\"In English\" title=\"In English\"/>\r\n\r\n\r\n\r\n <span style=\"position:absolute;right:0;top:0.05em;margin-right:1em;display:inline;font-size:0.75em;\">\r\n <div style=\"margin-top:0.25em;\">\r\n </div>\r\n </span>\r\n </div>\r\n\r\n <div class=\"content\">\r\n <div class=\"ttypography\"><p><a href=\"//codeforces.com/blog/entry/505\">Contest discussion</a></p><h3><strong>Problem ะ. Second Order Statistics</strong></h3><p><u>Sorting</u></p><p>In this problem one should find a minimal element from all elements, that are strictly greater, then the minimal one or report that it doesn't exist. Of course, there can be a lot of different solutions, but one of the simplest - to sort the given sequence and print the first element, that's not equal to the previous. If all elements are equal, then the required element doesn't exist.<strong><br /></strong></p><p> </p><h3>Problem B. Bargaining Table</h3><p><u>Simulation, dynamic programming</u></p><p>In this problem one should find the maximal perimeter of a rectangle that contains no '1'. Define these rectangles "correct". To solve a problem you are to check each possible rectangle for correctness and calculate its perimeter. The easiest way to check all rectangles is using 6 nested cycles. Using 4 of them you fix the coordinates while other 2 will look for '1'. So the complexity is O((n*m)<sup>3</sup>). It seems slow, but those, who wrote such a solution, says that it hasn't any problems with TL.<u><br /></u></p><p>One may interest in much faster solution. Using simple DP solution one can get a solution with an O((n*m)<sup>2</sup>) complexity. It's clear, that rectangle with coordinates (x1, y1, x2, y2) is correct if and only if rectangles (x1, y1, x2-1, y2) and (x1, y1, x2, y2-1) are correct, and board[x2][y2] = '0'. So each of rectangles can be checked in O(1) and totally there will be O((n*m)<sup>2</sup>) operations.</p><h3>Problem C. System Administrator</h3><p><u>Simulation</u></p><p>In this problem you are to construct a connected graph, which contains n vertexes and m edges, and if we delete vertex with number v, our graph stops being connected or to report that such a graph doesn't exist. Moreover, each pair of vertexes can have no more than one edge connecting them. Obviously, a connected graph doesn't exist if the number of edges is less than n-1. It's easy to notice, that the maximal possible number of edges reaches when there is a vertex connected to v and doesn't connected to any other vertex, those can form up to complete graph. So the maximal number of edges is (n-1)*(n-2)/2+1. If m is in that range then required graph always exists. Then you should place one vertex on the one side of v (let it be 1), and other vertexes - on the other side. First, you should connect all this vertexes to v and then connect them between each other (except 1).<u><br /></u></p><h3>Problem D. Segments</h3><p><u>Scanning line</u></p><p>In this problem one should place minimal number of points on the line such that any given segment touches at least one of these points. Let's call the coordinate of ending of any segment as event. There will be events of two types: beginning of a segment and its ending. Let's sort this events by coordinates. In the case of equality of some events consider that the event of the beginning will be less than the event of ending. Look at our events from left to right: if there is a beginning event, then push the number of this segment to the special queue. Once we take an ending of some segment, place the point here and clear the special queue (because each of segment in this queue will touch this point).<u><br /></u></p><h3>Problem E. Scheme</h3><p><u>Graph theory</u></p><p>Given an oriented graph, find the minimal number of edges one should add to this graph to make it strongly connected. Looking at statement we can get the fact that each vertex has exactly one outcoming edge. It means that starting at some point we'll get stuck in some cycle. So each connected (not strongly) component is a set of simple paths, ending in some cycle or just a simple cycle. First consider vertexes, which has no incoming edges. When passing through some vertex we'll paint it until the current vertex will be already painted. Then we call the starting vertex as "beginning" and the finishing one as "ending" of a component.<u><br /></u></p><p>After that consider other vertexes - they belong to cycles. Beginning and ending of a cycle - is any vertexes (possible coinciding) belonging to it. So we got a number of components which we have to connect. Let's connect them cyclically: the edge will pass from the ending of i-th component to the beginning of ((i+1)%k)-th, where k is the number of such components. The answer will be k. There is an exception: if we have only one component which is a simple cycle, the answer will be equal to 0.</p><p>So we'll consider each edge exactly once and the total complexity will be O(n).</p></div>\r\n\r\n </div>\r\n\r\n\r\n <div style=\"font-size: 1.1rem;line-height: 1.1rem;padding-bottom: 0.5em;\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/paperclip-16x16.png\" style=\"vertical-align: middle;\"/> <span style=\"padding: 0 0.35em;\">Tutorial of <a href=\"/contest/22\" class=\"notice\" style=\"text-decoration: none;\">Codeforces Beta Round 22 (Div. 2 Only)</a> </span>\r\n </div>\r\n \r\n <script type=\"text/javascript\">\n $(document).ready(function () {\n $(\".delete-resource-link-1448-507\").click(function() {\n var that = this;\n Codeforces.confirm(\"Are you sure you want to detach a contest?\", function () {\n $.post(\"/data/blogAndContest\", {\n action: \"detachBlogFromContest\",\n blogId: \"1448\",\n blogEntryId: \"507\",\n contestId: $(that).attr(\"data-contestId\"),\n resourceIds: $(that).attr(\"data-resourceIds\")\n }, function(json) { \n Codeforces.reloadAndShowMessageOrShowError(json, \"Contest detached\");\n });\n }, function () {}, \"Yes\", \"No\");\n });\n });\n</script>\r\n \r\n\r\n <div style=\"font-size: 1.1rem;line-height: 11px;\">\r\n <img style=\"vertical-align: middle;\" src=\"//codeforces.org/s/81027/images/blog/tags.png\" title=\"Tags\" alt=\"Tags\"/>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=beta+round+%2322\" class=\"tag notice\" style=\"text-decoration: none;\">beta round #22</a>,\r\n </span>\r\n <span style=\"padding: 0 0.35em;\">\r\n <a href=\"/search?query=tutorial\" class=\"tag notice\" style=\"text-decoration: none;\">tutorial</a>\r\n </span>\r\n </div>\r\n\r\n\n <div class=\"roundbox meta borderTopRound borderBottomRound\" style=\"\">\n <div class=\"left-meta\">\r\n <ul>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-up-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/voteup.png\"\n alt=\"Vote: I like it\" title=\"Vote: I like it\"\n /></a>\n\n\n</li>\r\n <li style=\"line-height: 1.6em;\">\n\n \n <span title=\"Topic rating\" style='font-size:larger;position:relative;bottom:1px;font-weight:bold;color:green'>+32</span>\n \n</li>\r\n <li style=\"line-height: 1.6em;\"> <a href=\"#\" class=\"topic-vote-down-507\"><img style=\"vertical-align:middle;position:relative;top:-0.2em\" src=\"//codeforces.org/s/81027/images/actions/votedown.png\"\n alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"\n /></a>\n\n\n</li>\r\n </ul>\r\n </div>\r\n\r\n\r\n <span style=\"position: relative; line-height: 1.65em; top: 0.75rem; left: 0.8em;\">\r\n </span>\r\n\r\n <div class=\"right-meta\">\r\n <ul>\r\n <li> <a href=\"/profile/iakolzin\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/user_16x16.png\"\n alt=\"Author\" title=\"Author\"\n /></a>\n\n\n <a href=\"/profile/iakolzin\">\n iakolzin\n </a>\n</li>\r\n <li> <img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/date_16x16.png\"\n alt=\"Publication date\" title=\"Publication date\"\n />\n\n\n \n <span class=\"format-humantime\" title=\"Jun/29/2010 22:08\">13 years ago</span>\n \n</li>\r\n <li> <a href=\"/blog/entry/507#comments\"><img style=\"vertical-align:middle;position:relative;top:-1px\" src=\"//codeforces.org/s/81027/images/blog/comments_16x16.png\"\n alt=\"Comments\" title=\"Comments\"\n /></a>\n\n\n <a href=\"/blog/entry/507#comments\">\n 18\n </a>\n</li>\r\n </ul>\r\n </div>\r\n\r\n <br style=\"clear:both;\"/>\r\n </div>\n\r\n\r\n<style type=\"text/css\">\r\n .comments .title {\r\n float: left;\r\n }\r\n\r\n .comments .comments-actions-div {\r\n float: right;\r\n margin-top: 3rem;\r\n margin-right: 0.5em;\r\n }\r\n\r\n .comments .comments-actions-div .separator {\r\n margin: 0 1rem;\r\n }\r\n\r\n .comments label.show-archived {\r\n }\r\n\r\n .comments label.show-archived, .comments label.show-archived * {\r\n font-size: 1.4rem !important;\r\n color: black !important;\r\n /*position: relative !important;*/\r\n /*bottom: 0.4rem !important;*/\r\n }\r\n\r\n .comments label.show-archived input {\r\n height: 1.4rem !important;\r\n width: 1.4rem !important;\r\n position: relative;\r\n top: 0.25rem;\r\n }\r\n\r\n .new-root-comment {\r\n font-size: 1.4rem !important;\r\n }\r\n</style>\r\n\r\n <div class=\"comments\" commentableId=\"517\">\r\n <div style=\"display: flow-root\">\r\n <div class=\"title\">\r\n <img src=\"//codeforces.org/s/81027/images/icons/comments-48x48.png\" alt=\"Comments\" title=\"Comments\"\r\n style=\"position:relative;top:0.6em;\"/>\r\n <a name=\"comments\">Comments (15)</a>\r\n\r\n </div>\r\n <div class=\"comments-actions-div\">\r\n <label class=\"show-archived\">\r\n <input type=\"checkbox\"\r\n class=\"show-archived-checkbox\" \n/>\r\n Show archived\r\n </label>\r\n <span class=\"separator\">|</span>\r\n <a href=\"#\" class=\"new-root-comment\"\r\n >Write comment?</a>\r\n </div>\r\n </div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7927\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jun/30/2010 22:30\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7927\" href=\"?#comment-7927\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7927\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"3\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+3</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7927\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Some of your types seem incorrect... Problems B and C are not simulation. Simulation involves running some sort of given process (usually efficiently), and neither of these problems involve that. B is brute force / DP, and C is graph theory.<br /><br />But the tutorial is great, thanks :) I can go fix my E now :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7927 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7927 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7927\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7943\" commentParentId=\"7927\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/yangfan\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/no-avatar.jpg'/> </a>\n <div><a href=\"/profile/yangfan\" title=\"Specialist yangfan\" class=\"rated-user user-cyan\">yangfan</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 02:59\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7943\" href=\"?#comment-7943\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7927\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7943\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"4604\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7943\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">I am not solving E with tutorial's method, and I got Wrong Answer on test 15 for a long time. Did U get any trouble on test 15? Thanks.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7943 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7943 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7943\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7956\" commentParentId=\"7943\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 07:40\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7956\" href=\"?#comment-7956\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7943\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7956\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7956\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">http://piratepad.net/ZosxPMMqyK<br /><br />There's my code for it. It passes 15, but gets RE on Test 22. I'm really not sure why. Tell me if you can find it, and hopefully it helps you with yours!</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7956 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7956 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7956\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7965\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Egor\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/838/avatar/6976bef0cdef7d5c.jpg'/><img title='Badge of honor for supporting Codeforces on its 10th anniversary' src='//codeforces.org/s/81027/images/if_medal-bronze-blue_46108.png' style='position:absolute;bottom:-4px;right:-6px'/> </a>\n <div><a href=\"/profile/Egor\" title=\"International Grandmaster Egor\" class=\"rated-user user-red\">Egor</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 12:17\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7965\" href=\"?#comment-7965\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7965\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"2\"\r\n data-commentUserId=\"838\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+2</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7965\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">You have stack overflow in dfs. Stack for default thread in java is not very big, you can avoid it by creating your own thread and executing code in it, like<div>class Sample implements Runnable {</div><div><span style=\"white-space: pre;\"> </span>public static void main(String[] args) {</div><div><span style=\"white-space: pre;\"> </span>new Thread(new Sample()).start();</div><div><span style=\"white-space: pre;\"> </span>}</div><div><br /></div><div><span style=\"white-space: pre;\"> </span>public void run() {</div><div><span style=\"white-space: pre;\"> </span>//Solution here</div><div><span style=\"white-space: pre;\"> </span>}</div><div>}</div><div><br /></div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7965 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7965 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7965\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7980\" commentParentId=\"7965\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/wjomlex\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3890/avatar/47df0da2a67f1863.jpg'/> </a>\n <div><a href=\"/profile/wjomlex\" title=\"Candidate Master wjomlex\" class=\"rated-user user-violet\">wjomlex</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 20:29\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7980\" href=\"?#comment-7980\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7965\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7980\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3890\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7980\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Thanks (to Ivan too)!<br /><br />I really shouldn't have missed that... though I didn't know that a new Thread could get extra stack space. Most interesting.<br /><br />I've got AC now and I've updated my code :D</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7980 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7980 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7980\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"7973\" commentParentId=\"7956\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ivan.popelyshev\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/73/avatar/dcae35722510f549.jpg'/> </a>\n <div><a href=\"/profile/ivan.popelyshev\" title=\"Master ivan.popelyshev\" class=\"rated-user user-orange\">ivan.popelyshev</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/01/2010 16:04\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-7973\" href=\"?#comment-7973\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-7956\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"7973\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"1\"\r\n data-commentUserId=\"73\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:green;font-weight:bold;\">+1</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-7973\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">new Thread(null, new Sample(), "1", 1<<23).start(); - 8 megabytes stack.</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-7973 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-7973 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-7973\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8053\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8053\" href=\"?#comment-8053\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8053\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8053\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">problem C may also be solved using a stack + dp, which gives an extremely fast O(mn) solution</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8053 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8053 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8053\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8054\" commentParentId=\"8053\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 10:09\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8054\" href=\"?#comment-8054\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8053\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8054\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8054\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">*problem B<div><br /></div><div>ps: there really should be an edit function for comments</div></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8054 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8054 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8054\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8133\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/Enric\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/49/avatar/8fd46dafe685edaa.jpg'/> </a>\n <div><a href=\"/profile/Enric\" title=\"Candidate Master Enric\" class=\"rated-user user-violet\">Enric</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/06/2010 20:03\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8133\" href=\"?#comment-8133\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8133\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"49\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8133\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">Could you give more details for the O(mn) solution?</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8133 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8133 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8133\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8142\" commentParentId=\"8133\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/random.johnnyh\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1558/avatar/1c5b4dd7d485b702.jpg'/> </a>\n <div><a href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\" class=\"rated-user user-orange\">random.johnnyh</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/07/2010 00:16\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8142\" href=\"?#comment-8142\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8133\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8142\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1558\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8142\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">its a fairly standard solution<br />its the same as the "largest rectangle in a histogram" problem except now you're looking for maximal perimeter, and you need to do a dp preprocessing<br />the "largest rectangle in a histogram" solution is here: http://homeofcox-cs.blogspot.com/2010/04/max-rectangle-in-histogram-problem.html</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8142 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8142 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-8142\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662663\" commentParentId=\"8142\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662663\" href=\"?#comment-662663\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8142\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662663\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662663\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-orange\" href=\"/profile/random.johnnyh\" title=\"Master random.johnnyh\">random.johnnyh</a> Can you please elucidate?</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662663 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662663 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662663\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"512470\" commentParentId=\"8054\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"May/19/2019 08:21\">4 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-512470\" href=\"?#comment-512470\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-8054\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"512470\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-512470\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>I have written this O(m*m*n) solution for problem B <a href=\"https://codeforces.com/contest/22/submission/54368605\">https://codeforces.com/contest/22/submission/54368605</a> I am unable to think of any better approach. Can you please provide working code for O(m*n) solution. Thanks in Advance.</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-512470 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-512470 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-512470\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662662\" commentParentId=\"512470\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/mehulcoder\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/1213610/avatar/9b3581c9d63c6b7a.jpg'/> </a>\n <div><a href=\"/profile/mehulcoder\" title=\"Expert mehulcoder\" class=\"rated-user user-blue\">mehulcoder</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 12:52\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662662\" href=\"?#comment-662662\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-512470\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662662\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"1213610\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662662\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p><a class=\"rated-user user-blue\" href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\">praveenojha33</a> Can you please give a short explanation of your code. Thanks in advance!</p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662662 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662662 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662662\">\r\n <li>\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"662743\" commentParentId=\"662662\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/praveenojha33\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/687087/avatar/f4330bc8d9012dda.jpg'/> </a>\n <div><a href=\"/profile/praveenojha33\" title=\"Expert praveenojha33\" class=\"rated-user user-blue\">praveenojha33</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/16/2020 16:15\">3 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-662743\" href=\"?#comment-662743\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\"><a title=\"Parent comment\" href=\"#comment-662662\" style=\"font-size:1.2em;\">^</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"662743\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"687087\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-662743\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\"><p>Do you know about maximum submatrix sum in a 2D matrix using Kadane Algorithm. If not you can watch it here <a href=\"https://www.youtube.com/watch?v=yCQN096CwWM\">https://www.youtube.com/watch?v=yCQN096CwWM</a></p><p>The problem is same as finding submatrix sum in 2D matrix this can be done using either O(n^4) approach using 2D prefix sum or using Kadane Algorithm in O(n^3). As you know Kadane Algorithm is O(n) and in 2D Kadane Algorithm we divide 2D matrix in n^2 submatrices that is from column (1-1),(1-2),(1-3),(1-4),(2-2),(2-3),(2-4),(3-3),(3-4),(4-4) and then apply kadane Algorithm to find max sum in that rectagular strip. </p></div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-662743 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-662743 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul class=\"comment-children comment-662743\">\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n</li>\r\n </ul>\r\n</div>\r\n\r\n<div class=\"comment\">\r\n <table class=\"comment-table\"\r\n commentId=\"8061\" commentParentId=\"-1\">\r\n <tr>\r\n <td class=\"left\">\r\n <div class=\"avatar\">\n <a href=\"/profile/ufo008ahw\" style=\"position: relative;\">\n<img src='https://userpic.codeforces.org/3037/avatar/99310deaab460f2b.jpg'/> </a>\n <div><a href=\"/profile/ufo008ahw\" title=\"Specialist ufo008ahw\" class=\"rated-user user-cyan\">ufo008ahw</a></div>\n </div>\n </td>\r\n <td class=\"right\">\r\n <div class=\"info\">\r\n \r\n <span class=\"item\"><span class=\"format-humantime\" title=\"Jul/04/2010 18:08\">13 years ago</span>,</span>\r\n <span class=\"item\"><a title=\"Link to comment\" name=\"comment-8061\" href=\"?#comment-8061\" style=\"font-size:1.2em;\">#</a></span>\r\n <span class=\"item\">|</span>\r\n <span style=\"position: relative; top: 2px;\">\r\n</span>\r\n <div style=\"position:absolute;right:0;top:0;\">\r\n \r\n\r\n<span commentid=\"8061\" class=\"CommentVoteFrame\"\r\n data-commentRating=\"0\"\r\n data-commentUserId=\"3037\"\r\n style=\"position:relative;\"\r\n>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"1\" dd=\"x\"><img style=\"position:relative;top:3px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-voteup-blue.png\" alt=\"Vote: I like it\" title=\"Vote: I like it\"/></a>\r\n<span class=\"commentRating\"><span style=\"color:gray;font-weight:bold;\">0</span></span>\r\n<a href=\"#\" class=\"vote-for-comment\" voteDirection=\"-1\" dd=\"y\"><img style=\"position:relative;top:2px;opacity:0.35;\" src=\"//codeforces.org/s/81027/images/actions/comment-votedown-blue.png\" alt=\"Vote: I do not like it\" title=\"Vote: I do not like it\"/></a>\r\n</span>\r\n </div>\r\n </div>\r\n <div class=\"comment-content comment-content-8061\">\r\n <div class=\"moveup\">\r\n <div class=\"ttypography\">the complexity of my solution of problem B is O(m^2 * n).</div>\r\n </div>\r\n </div>\r\n <div class=\"reply info\">\r\n <a class=\"comment-8061 en false\" href=\"#\" style=\"text-decoration: none;\"><span class=\"arrow\">→</span></a>\r\n <a class=\"comment-8061 en false\" href=\"#\">Reply</a>\r\n </div>\r\n </td>\r\n </tr>\r\n </table>\r\n <ul 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|---|---|---|---|---|---|---|---|---|---|---|
1A | 1 | A | en | A. Theatre Square | <div class="problem-statement"><div class="header"><div class="title">A. Theatre Square</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="dd8f97f9cdb3c4622dfbb26902f227c1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Mathematics including integration, differential equations, etc"] | ["math", "*1000"] | https://codeforces.com/blog/entry/85 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="5eeefb1609619e8976fdac828162c2b3"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
1B | 1 | B | en | B. Spreadsheets | <div class="problem-statement"><div class="header"><div class="title">B. Spreadsheets</div><div class="time-limit"><div class="property-title">time limit per test</div>10 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="p... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d8af891a43269681aa3e0746a3159904"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["implementation", "math", "*1600"] | https://codeforces.com/blog/entry/85 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="5eeefb1609619e8976fdac828162c2b3"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
1C | 1 | C | en | C. Ancient Berland Circus | <div class="problem-statement"><div class="header"><div class="title">C. Ancient Berland Circus</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0daee9db8e93716a4799e19281243744"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Geometry, computational geometry", "Mathematics including integration, differential equations, etc"] | ["geometry", "math", "*2100"] | https://codeforces.com/blog/entry/85 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="5eeefb1609619e8976fdac828162c2b3"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
2A | 2 | A | en | A. Winner | <div class="problem-statement"><div class="header"><div class="title">A. Winner</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="ee9ee0e9d0fe9dfea6f09f696bec4b65"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Hashing, hashtables", "Implementation problems, programming technics, simulation"] | ["hashing", "implementation", "*1500"] | https://codeforces.com/blog/entry/107 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="77b6975d9a52f7cdce63ee13aac9c39b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
2B | 2 | B | en | B. The least round way | <div class="problem-statement"><div class="header"><div class="title">B. The least round way</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cl... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="1ac4721f155060a0a49bdea36a4ced34"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Mathematics including integration, differential equations, etc"] | ["dp", "math", "*2000"] | https://codeforces.com/blog/entry/107 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="77b6975d9a52f7cdce63ee13aac9c39b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
2C | 2 | C | en | C. Commentator problem | <div class="problem-statement"><div class="header"><div class="title">C. Commentator problem</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f11f410ae7d7c26d830862a1d08ea79b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Geometry, computational geometry"] | ["geometry", "*2600"] | https://codeforces.com/blog/entry/107 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="77b6975d9a52f7cdce63ee13aac9c39b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
3A | 3 | A | en | A. Shortest path of the king | <div class="problem-statement"><div class="header"><div class="title">A. Shortest path of the king</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><d... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="b4d2747a67922cd839530d74ad4f532e"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Shortest paths on weighted and unweighted graphs"] | ["greedy", "shortest paths", "*1000"] | https://codeforces.com/blog/entry/192 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="6c0fc1dd483900324f3c6bd8903c56a9"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
3B | 3 | B | en | B. Lorry | <div class="problem-statement"><div class="header"><div class="title">B. Lorry</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="fd8915cd319c0d4ae77e4f3d16e2fe4a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Sortings, orderings"] | ["greedy", "sortings", "*1900"] | https://codeforces.com/blog/entry/192 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="6c0fc1dd483900324f3c6bd8903c56a9"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
3C | 3 | C | en | C. Tic-tac-toe | <div class="problem-statement"><div class="header"><div class="title">C. Tic-tac-toe</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prop... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="696a032764e684f1c6e516437c255340"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Games, Sprague\u2013Grundy theorem", "Implementation problems, programming technics, simulation"] | ["brute force", "games", "implementation", "*1800"] | https://codeforces.com/blog/entry/192 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="6c0fc1dd483900324f3c6bd8903c56a9"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
3D | 3 | D | en | D. Least Cost Bracket Sequence | <div class="problem-statement"><div class="header"><div class="title">D. Least Cost Bracket Sequence</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file">... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="8513014a8f9555c736ea457cd59e0530"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms"] | ["greedy", "*2600"] | https://codeforces.com/blog/entry/192 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="6c0fc1dd483900324f3c6bd8903c56a9"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
4A | 4 | A | en | A. Watermelon | <div class="problem-statement"><div class="header"><div class="title">A. Watermelon</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prope... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="300c82816d3c3bbe51aef3a48deb1105"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Mathematics including integration, differential equations, etc"] | ["brute force", "math", "*800"] | ||
4B | 4 | B | en | B. Before an Exam | <div class="problem-statement"><div class="header"><div class="title">B. Before an Exam</div><div class="time-limit"><div class="property-title">time limit per test</div>0.5 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class=... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="507df38748d783aecc4613befd989bbf"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Constructive algorithms", "Greedy algorithms"] | ["constructive algorithms", "greedy", "*1200"] | ||
4C | 4 | C | en | C. Registration system | <div class="problem-statement"><div class="header"><div class="title">C. Registration system</div><div class="time-limit"><div class="property-title">time limit per test</div>5 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cl... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="7fd3d6806a507ee4018284de13eb171c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc", "Hashing, hashtables", "Implementation problems, programming technics, simulation"] | ["data structures", "hashing", "implementation", "*1300"] | ||
4D | 4 | D | en | D. Mysterious Present | <div class="problem-statement"><div class="header"><div class="title">D. Mysterious Present</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div clas... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="22032fcb18494484c02bac490f190973"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Sortings, orderings"] | ["dp", "sortings", "*1700"] | ||
5A | 5 | A | en | A. Chat Server's Outgoing Traffic | <div class="problem-statement"><div class="header"><div class="title">A. Chat Server's Outgoing Traffic</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-fil... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="76fbb574fbcf23588e8bc715e6988886"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*1000"] | https://codeforces.com/blog/entry/213 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="51af0dfbf45e08f173f47d9761e0341a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
5B | 5 | B | en | B. Center Alignment | <div class="problem-statement"><div class="header"><div class="title">B. Center Alignment</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class=... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="cff9bed2518ad13af946539973deefb1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["implementation", "strings", "*1200"] | https://codeforces.com/blog/entry/213 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="51af0dfbf45e08f173f47d9761e0341a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
5C | 5 | C | en | C. Longest Regular Bracket Sequence | <div class="problem-statement"><div class="header"><div class="title">C. Longest Regular Bracket Sequence</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="9e2f54275b9361425af402b29a6043f1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Constructive algorithms", "Heaps, binary search trees, segment trees, hash tables, etc", "Dynamic programming", "Greedy algorithms", "Sortings, orderings", "Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["constructive algorithms", "data structures", "dp", "greedy", "sortings", "strings", "*1900"] | https://codeforces.com/blog/entry/213 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="51af0dfbf45e08f173f47d9761e0341a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
5D | 5 | D | en | D. Follow Traffic Rules | <div class="problem-statement"><div class="header"><div class="title">D. Follow Traffic Rules</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cl... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="8fc1f73ab5cbc2093f99eb410a39ebe0"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["implementation", "math", "*2100"] | https://codeforces.com/blog/entry/213 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="51af0dfbf45e08f173f47d9761e0341a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
5E | 5 | E | en | E. Bindian Signalizing | <div class="problem-statement"><div class="header"><div class="title">E. Bindian Signalizing</div><div class="time-limit"><div class="property-title">time limit per test</div>4 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div c... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="c9342ec63809fe2e5d9b71522f5f5c2d"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc"] | ["data structures", "*2400"] | https://codeforces.com/blog/entry/213 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="51af0dfbf45e08f173f47d9761e0341a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
6A | 6 | A | en | A. Triangle | <div class="problem-statement"><div class="header"><div class="title">A. Triangle</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d1875a83d957e3fd48b8b935ecab717b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Geometry, computational geometry"] | ["brute force", "geometry", "*900"] | https://codeforces.com/blog/entry/249 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="83363d6dcf8cad29485798bdbaa3c122"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
6B | 6 | B | en | B. President's Office | <div class="problem-statement"><div class="header"><div class="title">B. President's Office</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="79af7a98a1375ab438ce6e9799fb5f7f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*1100"] | https://codeforces.com/blog/entry/249 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="83363d6dcf8cad29485798bdbaa3c122"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
6C | 6 | C | en | C. Alice, Bob and Chocolate | <div class="problem-statement"><div class="header"><div class="title">C. Alice, Bob and Chocolate</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><d... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="cbacd2bfe4d59fbcc6385b68c145174a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Two pointers"] | ["greedy", "two pointers", "*1200"] | https://codeforces.com/blog/entry/249 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="83363d6dcf8cad29485798bdbaa3c122"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
6D | 6 | D | en | D. Lizards and Basements 2 | <div class="problem-statement"><div class="header"><div class="title">D. Lizards and Basements 2</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><di... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="de53ff9c6a7f53158fdb8c19782a2b94"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Dynamic programming"] | ["brute force", "dp", "*2600"] | https://codeforces.com/blog/entry/249 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="83363d6dcf8cad29485798bdbaa3c122"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
6E | 6 | E | en | E. Exposition | <div class="problem-statement"><div class="header"><div class="title">E. Exposition</div><div class="time-limit"><div class="property-title">time limit per test</div>1.5 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="pr... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="74c939d14dfe8758fecdfa0cf31feeab"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Binary search", "Heaps, binary search trees, segment trees, hash tables, etc", "Disjoint set union", "Trees", "Two pointers"] | ["binary search", "data structures", "dsu", "trees", "two pointers", "*1900"] | https://codeforces.com/blog/entry/249 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="83363d6dcf8cad29485798bdbaa3c122"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
7A | 7 | A | en | A. Kalevitch and Chess | <div class="problem-statement"><div class="header"><div class="title">A. Kalevitch and Chess</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cl... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="951c0a0b1a562fa0f46a21ec1d49556b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Constructive algorithms"] | ["brute force", "constructive algorithms", "*1100"] | ||
7B | 7 | B | en | B. Memory Manager | <div class="problem-statement"><div class="header"><div class="title">B. Memory Manager</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="p... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e3453dbba49291749dea22e26670d36f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*1600"] | ||
7C | 7 | C | en | C. Line | <div class="problem-statement"><div class="header"><div class="title">C. Line</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="property-t... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="054d11bff13aeaa3e6176b13add38f67"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Mathematics including integration, differential equations, etc", "Number theory: Euler function, GCD, divisibility, etc"] | ["math", "number theory", "*1800"] | ||
7D | 7 | D | en | D. Palindrome Degree | <div class="problem-statement"><div class="header"><div class="title">D. Palindrome Degree</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div clas... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="b23eb534398a0def97e8a640724e509f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Hashing, hashtables", "Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["hashing", "strings", "*2200"] | ||
7E | 7 | E | en | E. Defining Macros | <div class="problem-statement"><div class="header"><div class="title">E. Defining Macros</div><div class="time-limit"><div class="property-title">time limit per test</div>3 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="c73366e183570ad43900a564e99e46ac"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Parsing expression grammar", "Implementation problems, programming technics, simulation"] | ["dp", "expression parsing", "implementation", "*2600"] | ||
8A | 8 | A | en | A. Train and Peter | <div class="problem-statement"><div class="header"><div class="title">A. Train and Peter</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="9895353116bd5b3ad9b86785d83e45f3"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["strings", "*1200"] | https://codeforces.com/blog/entry/4441 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="73191ab8f80cda1ffbb96ceb493c164c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
8B | 8 | B | en | B. Obsession with Robots | <div class="problem-statement"><div class="header"><div class="title">B. Obsession with Robots</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div ... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="ea7ffd901222eaa723dd8f34bdf6596c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Constructive algorithms", "Graphs", "Implementation problems, programming technics, simulation"] | ["constructive algorithms", "graphs", "implementation", "*1400"] | https://codeforces.com/blog/entry/4441 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="73191ab8f80cda1ffbb96ceb493c164c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
8C | 8 | C | en | C. Looking for Order | <div class="problem-statement"><div class="header"><div class="title">C. Looking for Order</div><div class="time-limit"><div class="property-title">time limit per test</div>4 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>512 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="851fbd9d09e4fbb885ef520844aa4fc0"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Bitmasks", "Dynamic programming"] | ["bitmasks", "dp", "*2000"] | https://codeforces.com/blog/entry/4441 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="73191ab8f80cda1ffbb96ceb493c164c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
8D | 8 | D | en | D. Two Friends | <div class="problem-statement"><div class="header"><div class="title">D. Two Friends</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prop... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="7c31e5dfdbd8ce7d0a37c208bd50e582"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Binary search", "Geometry, computational geometry"] | ["binary search", "geometry", "*2600"] | https://codeforces.com/blog/entry/4441 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="73191ab8f80cda1ffbb96ceb493c164c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
8E | 8 | E | en | E. Beads | <div class="problem-statement"><div class="header"><div class="title">E. Beads</div><div class="time-limit"><div class="property-title">time limit per test</div>5 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="038e907038a38f6e084c589b51182853"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Graphs"] | ["dp", "graphs", "*2600"] | https://codeforces.com/blog/entry/4441 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="73191ab8f80cda1ffbb96ceb493c164c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
9A | 9 | A | en | A. Die Roll | <div class="problem-statement"><div class="header"><div class="title">A. Die Roll</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="a4eb42f091675aaefe402a689a406376"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Mathematics including integration, differential equations, etc", "Probabilities, expected values, statistics, random variables, etc"] | ["math", "probabilities", "*800"] | https://codeforces.com/blog/entry/283 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d79f63851f5aac1bc3efc604e0fdc684"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
9B | 9 | B | en | B. Running Student | <div class="problem-statement"><div class="header"><div class="title">B. Running Student</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="79dc5480abb094848d709e91f4ab7bc1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Geometry, computational geometry", "Implementation problems, programming technics, simulation"] | ["brute force", "geometry", "implementation", "*1200"] | https://codeforces.com/blog/entry/283 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d79f63851f5aac1bc3efc604e0fdc684"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
9C | 9 | C | en | C. Hexadecimal's Numbers | <div class="problem-statement"><div class="header"><div class="title">C. Hexadecimal's Numbers</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div c... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2dca3587a38808a742ded095e4779248"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["brute force", "implementation", "math", "*1200"] | https://codeforces.com/blog/entry/283 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d79f63851f5aac1bc3efc604e0fdc684"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
9D | 9 | D | en | D. How many trees? | <div class="problem-statement"><div class="header"><div class="title">D. How many trees?</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="c4211d8631c7d98ad35dbeeda0348f5a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Combinatorics", "Divide and Conquer", "Dynamic programming"] | ["combinatorics", "divide and conquer", "dp", "*1900"] | https://codeforces.com/blog/entry/283 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d79f63851f5aac1bc3efc604e0fdc684"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
9E | 9 | E | en | E. Interesting Graph and Apples | <div class="problem-statement"><div class="header"><div class="title">E. Interesting Graph and Apples</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="1958f451065240336403a07e04c899fc"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dfs and similar", "Disjoint set union", "Graphs"] | ["dfs and similar", "dsu", "graphs", "*2300"] | https://codeforces.com/blog/entry/283 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d79f63851f5aac1bc3efc604e0fdc684"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
10A | 10 | A | en | A. Power Consumption Calculation | <div class="problem-statement"><div class="header"><div class="title">A. Power Consumption Calculation</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-fil... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="900411579ee7bf81f1f72496c507c233"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*900"] | ||
10B | 10 | B | en | B. Cinema Cashier | <div class="problem-statement"><div class="header"><div class="title">B. Cinema Cashier</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="8150fa789cb3784c02aa986efa232cdf"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Implementation problems, programming technics, simulation"] | ["dp", "implementation", "*1500"] | ||
10C | 10 | C | en | C. Digital Root | <div class="problem-statement"><div class="header"><div class="title">C. Digital Root</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="p... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="1c0b3a69d64a129a57162b969e7a0a4b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Number theory: Euler function, GCD, divisibility, etc"] | ["number theory", "*2000"] | ||
10D | 10 | D | en | D. LCIS | <div class="problem-statement"><div class="header"><div class="title">D. LCIS</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="property-t... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="548b0d0a010fe1d3bac912c6a5538d60"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming"] | ["dp", "*2800"] | ||
10E | 10 | E | en | E. Greedy Change | <div class="problem-statement"><div class="header"><div class="title">E. Greedy Change</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="91261339669aeef7e91e849286daabe5"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Constructive algorithms"] | ["constructive algorithms", "*2600"] | ||
11A | 11 | A | en | A. Increasing Sequence | <div class="problem-statement"><div class="header"><div class="title">A. Increasing Sequence</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d07d33e86d4a97d44e5df35f746e4ba2"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Constructive algorithms", "Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["constructive algorithms", "implementation", "math", "*900"] | ||
11B | 11 | B | en | B. Jumping Jack | <div class="problem-statement"><div class="header"><div class="title">B. Jumping Jack</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="pro... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="1712ccbf48e3df68efb27533bef773e0"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Mathematics including integration, differential equations, etc"] | ["math", "*1600"] | ||
11C | 11 | C | en | C. How Many Squares? | <div class="problem-statement"><div class="header"><div class="title">C. How Many Squares?</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div clas... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0864f5f28cb16582dc5945f39fadf579"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*2200"] | ||
11D | 11 | D | en | D. A Simple Task | <div class="problem-statement"><div class="header"><div class="title">D. A Simple Task</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="664b5c05900fbfb1da3a85a3c485cd86"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Bitmasks", "Dynamic programming", "Graphs"] | ["bitmasks", "dp", "graphs", "*2200"] | ||
11E | 11 | E | en | E. Forward, march! | <div class="problem-statement"><div class="header"><div class="title">E. Forward, march!</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="aea3bedf639926d2c60947887a22f9da"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Binary search", "Dynamic programming", "Greedy algorithms"] | ["binary search", "dp", "greedy", "*2800"] | ||
12A | 12 | A | en | A. Super Agent | <div class="problem-statement"><div class="header"><div class="title">A. Super Agent</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="pr... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="722444286749afaa333e7cdbd64e66a2"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*800"] | ||
12B | 12 | B | en | B. Correct Solution? | <div class="problem-statement"><div class="header"><div class="title">B. Correct Solution?</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="5be4aa8ef968a6088da2c9dac1d899c1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Sortings, orderings"] | ["implementation", "sortings", "*1100"] | ||
12C | 12 | C | en | C. Fruits | <div class="problem-statement"><div class="header"><div class="title">C. Fruits</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="property... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="62343a5e8b87053f158e6c8a51659ac7"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Implementation problems, programming technics, simulation", "Sortings, orderings"] | ["greedy", "implementation", "sortings", "*1100"] | ||
12D | 12 | D | en | D. Ball | <div class="problem-statement"><div class="header"><div class="title">D. Ball</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="property-... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2b222aeb3a37cd47e31df324544295b2"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc", "Sortings, orderings"] | ["data structures", "sortings", "*2400"] | ||
12E | 12 | E | en | E. Start of the season | <div class="problem-statement"><div class="header"><div class="title">E. Start of the season</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div c... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="6b5c16aa011ba06efcd1ae97f03625d3"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Constructive algorithms"] | ["constructive algorithms", "*2100"] | ||
13A | 13 | A | en | A. Numbers | <div class="problem-statement"><div class="header"><div class="title">A. Numbers</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="8e82f2ac47cdeea58ce74cce0701b096"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["implementation", "math", "*1000"] | https://codeforces.com/blog/entry/364 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e7172c98c22725553672e998425554b8"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
13B | 13 | B | en | B. Letter A | <div class="problem-statement"><div class="header"><div class="title">B. Letter A</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="39c8b340b9771302f248591ba43c0079"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Geometry, computational geometry", "Implementation problems, programming technics, simulation"] | ["geometry", "implementation", "*2000"] | https://codeforces.com/blog/entry/364 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e7172c98c22725553672e998425554b8"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
13C | 13 | C | en | C. Sequence | <div class="problem-statement"><div class="header"><div class="title">C. Sequence</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="06d6da9090c864448128053cb06a3333"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Sortings, orderings"] | ["dp", "sortings", "*2200"] | https://codeforces.com/blog/entry/364 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e7172c98c22725553672e998425554b8"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
13D | 13 | D | en | D. Triangles | <div class="problem-statement"><div class="header"><div class="title">D. Triangles</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prope... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="d11ff5231f02c754f9919da0b89fef7f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming", "Geometry, computational geometry"] | ["dp", "geometry", "*2600"] | https://codeforces.com/blog/entry/364 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e7172c98c22725553672e998425554b8"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
13E | 13 | E | en | E. Holes | <div class="problem-statement"><div class="header"><div class="title">E. Holes</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-t... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="812afc22e781451b13ea2c689a92d6f8"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc", "Disjoint set union"] | ["data structures", "dsu", "*2700"] | https://codeforces.com/blog/entry/364 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e7172c98c22725553672e998425554b8"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
14A | 14 | A | en | A. Letter | <div class="problem-statement"><div class="header"><div class="title">A. Letter</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="742d8cad38a60f630c95d7ace2c20aa2"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*800"] | https://codeforces.com/blog/entry/389 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0213eace8fc11974737662f82188969a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
14B | 14 | B | en | B. Young Photographer | <div class="problem-statement"><div class="header"><div class="title">B. Young Photographer</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0dc6a057fe3e077b439c6059fe949087"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*1000"] | https://codeforces.com/blog/entry/389 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0213eace8fc11974737662f82188969a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
14C | 14 | C | en | C. Four Segments | <div class="problem-statement"><div class="header"><div class="title">C. Four Segments</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="p... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e98f4356edb511df379e39a2f064c413"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Constructive algorithms", "Geometry, computational geometry", "Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["brute force", "constructive algorithms", "geometry", "implementation", "math", "*1700"] | https://codeforces.com/blog/entry/389 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0213eace8fc11974737662f82188969a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
14D | 14 | D | en | D. Two Paths | <div class="problem-statement"><div class="header"><div class="title">D. Two Paths</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prope... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="05d6a562095499eae5899f196732d81c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dfs and similar", "Dynamic programming", "Graphs", "Shortest paths on weighted and unweighted graphs", "Trees", "Two pointers"] | ["dfs and similar", "dp", "graphs", "shortest paths", "trees", "two pointers", "*1900"] | https://codeforces.com/blog/entry/389 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0213eace8fc11974737662f82188969a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
14E | 14 | E | en | E. Camels | <div class="problem-statement"><div class="header"><div class="title">E. Camels</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="7252f0f731c1cff180aedfd7f4956611"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming"] | ["dp", "*1900"] | https://codeforces.com/blog/entry/389 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="0213eace8fc11974737662f82188969a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
15A | 15 | A | en | A. Cottage Village | <div class="problem-statement"><div class="header"><div class="title">A. Cottage Village</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class=... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="12c91f5917523cfebe16d72dfb10ea65"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Sortings, orderings"] | ["implementation", "sortings", "*1200"] | https://codeforces.com/blog/entry/411 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="526752e7c14b5be5b9bfaea946f6b2d1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
15B | 15 | B | en | B. Laser | <div class="problem-statement"><div class="header"><div class="title">B. Laser</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-t... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="77bdd7065136ce686a3832574be47195"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Mathematics including integration, differential equations, etc"] | ["math", "*1800"] | https://codeforces.com/blog/entry/411 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="526752e7c14b5be5b9bfaea946f6b2d1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
15C | 15 | C | en | C. Industrial Nim | <div class="problem-statement"><div class="header"><div class="title">C. Industrial Nim</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="18ab5b36f6e8a9f36faa40d7f92f36ad"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Games, Sprague\u2013Grundy theorem"] | ["games", "*2000"] | https://codeforces.com/blog/entry/411 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="526752e7c14b5be5b9bfaea946f6b2d1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
15D | 15 | D | en | D. Map | <div class="problem-statement"><div class="header"><div class="title">D. Map</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>128 megabytes</div><div class="input-file"><div class="property-t... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="34091cdd1d6fbfbd9099264fc89ae72c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc", "Implementation problems, programming technics, simulation", "Sortings, orderings"] | ["data structures", "implementation", "sortings", "*2500"] | https://codeforces.com/blog/entry/411 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="526752e7c14b5be5b9bfaea946f6b2d1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
15E | 15 | E | en | E. Triangles | <div class="problem-statement"><div class="header"><div class="title">E. Triangles</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f2ee5e06cfb20e1a788aa7e1c2f686f5"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Combinatorics", "Dynamic programming"] | ["combinatorics", "dp", "*2600"] | https://codeforces.com/blog/entry/411 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="526752e7c14b5be5b9bfaea946f6b2d1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
16A | 16 | A | en | A. Flag | <div class="problem-statement"><div class="header"><div class="title">A. Flag</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property-t... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="4cf8e0d671882a9013e79446a8ccee53"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*800"] | https://codeforces.com/blog/entry/431 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2e03790445a5a5b0be02ccd5f8aaf33e"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
16B | 16 | B | en | B. Burglar and Matches | <div class="problem-statement"><div class="header"><div class="title">B. Burglar and Matches</div><div class="time-limit"><div class="property-title">time limit per test</div>0.5 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div c... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="69b18e2169fb64b67c4a94f6e4aab197"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Implementation problems, programming technics, simulation", "Sortings, orderings"] | ["greedy", "implementation", "sortings", "*900"] | https://codeforces.com/blog/entry/431 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2e03790445a5a5b0be02ccd5f8aaf33e"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
16C | 16 | C | en | C. Monitor | <div class="problem-statement"><div class="header"><div class="title">C. Monitor</div><div class="time-limit"><div class="property-title">time limit per test</div>0.5 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="972cd635f59959951bfae03f2cb6c0b4"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Binary search", "Number theory: Euler function, GCD, divisibility, etc"] | ["binary search", "number theory", "*1800"] | https://codeforces.com/blog/entry/431 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2e03790445a5a5b0be02ccd5f8aaf33e"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
16D | 16 | D | en | D. Logging | <div class="problem-statement"><div class="header"><div class="title">D. Logging</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="84330913f3980fec8462d0061f4cf7aa"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["implementation", "strings", "*1900"] | https://codeforces.com/blog/entry/431 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2e03790445a5a5b0be02ccd5f8aaf33e"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
16E | 16 | E | en | E. Fish | <div class="problem-statement"><div class="header"><div class="title">E. Fish</div><div class="time-limit"><div class="property-title">time limit per test</div>3 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>128 megabytes</div><div class="input-file"><div class="property-... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="4e8f50ae636c4dd5f2b66b618d2bc10a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Bitmasks", "Dynamic programming", "Probabilities, expected values, statistics, random variables, etc"] | ["bitmasks", "dp", "probabilities", "*1900"] | https://codeforces.com/blog/entry/431 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="2e03790445a5a5b0be02ccd5f8aaf33e"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
17A | 17 | A | en | A. Noldbach problem | <div class="problem-statement"><div class="header"><div class="title">A. Noldbach problem</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="c0baae575d518f59eca3ebf53bd1d511"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Mathematics including integration, differential equations, etc", "Number theory: Euler function, GCD, divisibility, etc"] | ["brute force", "math", "number theory", "*1000"] | https://codeforces.com/blog/entry/451 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="db02a831347ebee346bb8256eecc937c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
17B | 17 | B | en | B. Hierarchy | <div class="problem-statement"><div class="header"><div class="title">B. Hierarchy</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prope... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="307af9617cc4d9d7edd61b78b72cd485"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dfs and similar", "Disjoint set union", "Greedy algorithms", "Shortest paths on weighted and unweighted graphs"] | ["dfs and similar", "dsu", "greedy", "shortest paths", "*1500"] | https://codeforces.com/blog/entry/451 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="db02a831347ebee346bb8256eecc937c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
17C | 17 | C | en | C. Balance | <div class="problem-statement"><div class="header"><div class="title">C. Balance</div><div class="time-limit"><div class="property-title">time limit per test</div>3 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>128 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="1c29e8c98952a4365227c5e7f79027ee"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming"] | ["dp", "*2500"] | https://codeforces.com/blog/entry/451 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="db02a831347ebee346bb8256eecc937c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
17D | 17 | D | en | D. Notepad | <div class="problem-statement"><div class="header"><div class="title">D. Notepad</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="21dd5aec792bdaacbd07a2cabaed9731"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Number theory: Euler function, GCD, divisibility, etc"] | ["number theory", "*2400"] | https://codeforces.com/blog/entry/451 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="db02a831347ebee346bb8256eecc937c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
17E | 17 | E | en | E. Palisection | <div class="problem-statement"><div class="header"><div class="title">E. Palisection</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>128 megabytes</div><div class="input-file"><div class="pr... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="30bd80e906a93a808a58c9100cc59e00"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["strings", "*2900"] | https://codeforces.com/blog/entry/451 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="db02a831347ebee346bb8256eecc937c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
18A | 18 | A | en | A. Triangle | <div class="problem-statement"><div class="header"><div class="title">A. Triangle</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="c781445b6d909d491720a1860bdfdc22"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Geometry, computational geometry"] | ["brute force", "geometry", "*1500"] | https://codeforces.com/blog/entry/463 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f8524db49153144b45c3d5e056bc183c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
18B | 18 | B | en | B. Platforms | <div class="problem-statement"><div class="header"><div class="title">B. Platforms</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="prope... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="30f3cb23da328a3f62da5938d30233d0"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Mathematics including integration, differential equations, etc"] | ["brute force", "math", "*1700"] | https://codeforces.com/blog/entry/463 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f8524db49153144b45c3d5e056bc183c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
18C | 18 | C | en | C. Stripe | <div class="problem-statement"><div class="header"><div class="title">C. Stripe</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="property... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="79c5a28556c90c3909fbb6d5cf292cd7"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc", "Implementation problems, programming technics, simulation"] | ["data structures", "implementation", "*1200"] | https://codeforces.com/blog/entry/463 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f8524db49153144b45c3d5e056bc183c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
18D | 18 | D | en | D. Seller Bob | <div class="problem-statement"><div class="header"><div class="title">D. Seller Bob</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>128 megabytes</div><div class="input-file"><div class="pro... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="582bdd04ae1da93f6044e1fc34e1b16b"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Dynamic programming", "Greedy algorithms"] | ["brute force", "dp", "greedy", "*2000"] | https://codeforces.com/blog/entry/463 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f8524db49153144b45c3d5e056bc183c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
18E | 18 | E | en | E. Flag 2 | <div class="problem-statement"><div class="header"><div class="title">E. Flag 2</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>128 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="5693d9de35d869c4c3625e96ff3bc8f2"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming"] | ["dp", "*2000"] | https://codeforces.com/blog/entry/463 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="f8524db49153144b45c3d5e056bc183c"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
19A | 19 | A | en | A. World Football Cup | <div class="problem-statement"><div class="header"><div class="title">A. World Football Cup</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="e0db35c8d3f391d4dc7806d59c702452"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*1400"] | https://codeforces.com/blog/entry/559 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="36b8243f0044940680edefae5a855cb6"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
19B | 19 | B | en | B. Checkout Assistant | <div class="problem-statement"><div class="header"><div class="title">B. Checkout Assistant</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div cla... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="ae2e98834bf528d5c15d2c4f08dc95a1"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dynamic programming"] | ["dp", "*1900"] | https://codeforces.com/blog/entry/559 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="36b8243f0044940680edefae5a855cb6"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
19C | 19 | C | en | C. Deletion of Repeats | <div class="problem-statement"><div class="header"><div class="title">C. Deletion of Repeats</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div c... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="49e88472d2be9fd048091108dd25aa16"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Hashing, hashtables", "Suffix arrays, suffix trees, suffix automatas, etc"] | ["greedy", "hashing", "string suffix structures", "*2200"] | https://codeforces.com/blog/entry/559 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="36b8243f0044940680edefae5a855cb6"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
19D | 19 | D | en | D. Points | <div class="problem-statement"><div class="header"><div class="title">D. Points</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="a052c9fdd9ccb59f6eb4e5b0eb22e346"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Heaps, binary search trees, segment trees, hash tables, etc"] | ["data structures", "*2800"] | https://codeforces.com/blog/entry/559 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="36b8243f0044940680edefae5a855cb6"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
19E | 19 | E | en | E. Fairy | <div class="problem-statement"><div class="header"><div class="title">E. Fairy</div><div class="time-limit"><div class="property-title">time limit per test</div>1.5 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="25e78214d2b357b5d8fe6a0922bb10db"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Dfs and similar", "Divide and Conquer", "Disjoint set union"] | ["dfs and similar", "divide and conquer", "dsu", "*2900"] | https://codeforces.com/blog/entry/559 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="36b8243f0044940680edefae5a855cb6"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
20A | 20 | A | en | A. BerOS file system | <div class="problem-statement"><div class="header"><div class="title">A. BerOS file system</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div clas... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="ff112d6f554b4da54c38769846af3c17"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation"] | ["implementation", "*1700"] | ||
20B | 20 | B | en | B. Equation | <div class="problem-statement"><div class="header"><div class="title">B. Equation</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="973bb180c6266e8406fed362f34b1b28"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Mathematics including integration, differential equations, etc"] | ["math", "*2000"] | ||
20C | 20 | C | en | C. Dijkstra? | <div class="problem-statement"><div class="header"><div class="title">C. Dijkstra?</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="248d8a243b5ead634f17e7e86c1d5f7a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Graphs", "Shortest paths on weighted and unweighted graphs"] | ["graphs", "shortest paths", "*1900"] | ||
21A | 21 | A | en | A. Jabber ID | <div class="problem-statement"><div class="header"><div class="title">A. Jabber ID</div><div class="time-limit"><div class="property-title">time limit per test</div>0.5 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="pro... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="62792626563ec00f5ae323f28db0d69a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Prefix- and Z-functions, suffix structures, Knuth\u2013Morris\u2013Pratt algorithm, etc"] | ["implementation", "strings", "*1900"] | ||
21B | 21 | B | en | B. Intersection | <div class="problem-statement"><div class="header"><div class="title">B. Intersection</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="pr... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="ce7f23b6691badefb891c2e27a65901a"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Implementation problems, programming technics, simulation", "Mathematics including integration, differential equations, etc"] | ["implementation", "math", "*2000"] | ||
21C | 21 | C | en | C. Stripe 2 | <div class="problem-statement"><div class="header"><div class="title">C. Stripe 2</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class="propert... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="5b827220500ab8b739dcc38afc3aa999"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Binary search", "Dynamic programming", "Sortings, orderings"] | ["binary search", "dp", "sortings", "*2000"] | ||
21D | 21 | D | en | D. Traveling Graph | <div class="problem-statement"><div class="header"><div class="title">D. Traveling Graph</div><div class="time-limit"><div class="property-title">time limit per test</div>0.5 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>64 megabytes</div><div class="input-file"><div class... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="fb06fae9b5ff44c974e3833c8d612905"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Bitmasks", "Graph matchings, K\u00f6nig's theorem, vertex cover of bipartite graph", "Graphs"] | ["bitmasks", "graph matchings", "graphs", "*2400"] | ||
22A | 22 | A | en | A. Second Order Statistics | <div class="problem-statement"><div class="header"><div class="title">A. Second Order Statistics</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><d... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="7d0720cc9b2fae6263015c0b52bcecd0"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force"] | ["brute force", "*800"] | https://codeforces.com/blog/entry/507 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="24bfa389977bffbbea433287f885534f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
22B | 22 | B | en | B. Bargaining Table | <div class="problem-statement"><div class="header"><div class="title">B. Bargaining Table</div><div class="time-limit"><div class="property-title">time limit per test</div>2 seconds</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div clas... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="894b5bcb46678f5e8f9a869c0e39ef94"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Brute force", "Dynamic programming"] | ["brute force", "dp", "*1500"] | https://codeforces.com/blog/entry/507 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="24bfa389977bffbbea433287f885534f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
22C | 22 | C | en | C. System Administrator | <div class="problem-statement"><div class="header"><div class="title">C. System Administrator</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div c... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="09e227c2b315b524d03167adf1d37c65"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Graphs"] | ["graphs", "*1700"] | https://codeforces.com/blog/entry/507 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="24bfa389977bffbbea433287f885534f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
22D | 22 | D | en | D. Segments | <div class="problem-statement"><div class="header"><div class="title">D. Segments</div><div class="time-limit"><div class="property-title">time limit per test</div>1 second</div><div class="memory-limit"><div class="property-title">memory limit per test</div>256 megabytes</div><div class="input-file"><div class="proper... |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="24180175d2452780123da73242a5c588"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... | ["Greedy algorithms", "Sortings, orderings"] | ["greedy", "sortings", "*1900"] | https://codeforces.com/blog/entry/507 |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta name="X-Csrf-Token" content="24bfa389977bffbbea433287f885534f"/>
<meta id="viewport" name="viewport" content="width=device-width, initial-scale=0.01"/>
... |
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