{"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":"Iahub觉得无聊,于是他发明了一个纸上谈兵的游戏。\n\n他写n个整数a1, a2, …, an。这些整数可以是0或1。他只允许做一次移动:他选择两个指数i和j(1≤ i≤ j≤ n),并翻转其位置在[i, j]范围内的所有值ak(即i≤ k ≤ j)。翻转x的值意味着应用操作x \u003d 1-x。\n\n游戏的目标是在一次移动后获得最多的1。编写一个程序来解决Iahub的小游戏。"}},{"title":"Input","value":{"format":"HTML","content":"输入的第一行包含一个整数n(1≤ n≤ 100)。在输入的第二行有n个整数:a1, a2, …, an。可以保证这些n个值中的每一个都是0或1。"}},{"title":"Output","value":{"format":"HTML","content":"输出经过一次移动后可以获得的最大数量的1。"}},{"title":"Examples","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\u003e5\u003cbr\u003e1 0 0 1 0\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\u003e4\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n \u003cdiv class\u003d\"input\"\u003e\n \u003cdiv class\u003d\"title\"\u003e\n Input\n \u003c/div\u003e\n \u003cpre\u003e4\u003cbr\u003e1 0 0 1\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\u003e4\u003cbr\u003e\u003c/pre\u003e\n \u003c/div\u003e\n\u003c/div\u003e"}}]}