{"trustable":false,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"给定 N 个灯,每个灯都有两种状态(开/关)\u003cbr\u003e第 i 个灯的编号为 i,起初所有灯都是亮的\n\u003cbr\u003e现在有 K 次操作,每次操作给定一个数 x\n要求把编号为 x 的倍数的灯的状态改变 ( 开 → 关,关 → 开)\n\u003cbr\u003e问整个过程中灯最多关闭了几盏"}},{"title":"Input","value":{"format":"HTML","content":"输入由几行组成,每行由一个整数组成:\u003cbr\u003e\n第一行表示N个灯光。1≤N≤1000000。\u003cbr\u003e\n第二行表示操作次数k。1≤k≤100。\u003cbr\u003e\n接下来的k行每行表示给定的数 X 。"}},{"title":"Output","value":{"format":"HTML","content":"输出应该由一行组成,其内容是一个整数,即同时关闭的最大数量的灯光。"}},{"title":"Example","value":{"format":"HTML","content":"\u003cdiv class\u003d\"sample-test\"\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e10\u003cbr\u003e4\u003cbr\u003e6\u003cbr\u003e2\u003cbr\u003e1\u003cbr\u003e3\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"output\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Output\n \u003c/div\u003e\n \u003cpre\u003e6\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n\u003c/div\u003e"}},{"title":"Note","value":{"format":"HTML","content":"\u003cp\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eSample Explanation:\u003c/span\u003e\u003c/p\u003e\n\u003cp\u003eWe start with a group of 10 lights which are all on. \u003c/p\u003e\n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/ac7a9a3708e3725e1471e5a5589c357c?v\u003d1600677585\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e The hackers send the number 6: light 6 is toggled. \n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/41b1b3403dc43e83db7d9b107ab1d8b1?v\u003d1600677585\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e They then send the number 2: lights 2, 4, 6, 8, and 10 are toggled. \n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/837f874477175e1f86bf34d20ea8dff4?v\u003d1600677585\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e The number 1 is then sent: all lights are toggled. \n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/4aedcc65c2404ac8359cc9511808f277?v\u003d1600677585\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e They end up sending the number 3: lights 3, 6, and 9 are toggled. \n\u003ccenter\u003e \n \u003cimg class\u003d\"tex-graphics\" src\u003d\"CDN_BASE_URL/c026b026d403960e20443e527529c96f?v\u003d1600677585\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e \n\u003c/center\u003e The maximum number of lights off at the same time was 6."}}]}