{"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":"\u003cp\u003eMemory is performing a walk on the two-dimensional plane, starting at the origin. He is given a string \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e\u003c/span\u003e with his directions for motion:\u003c/p\u003e\u003cul\u003e\u003cli\u003e An \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eL\u003c/span\u003e\u0027 indicates he should move one unit left. \u003c/li\u003e\u003cli\u003e An \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eR\u003c/span\u003e\u0027 indicates he should move one unit right. \u003c/li\u003e\u003cli\u003e A \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eU\u003c/span\u003e\u0027 indicates he should move one unit up. \u003c/li\u003e\u003cli\u003e A \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eD\u003c/span\u003e\u0027 indicates he should move one unit down.\u003c/li\u003e\u003c/ul\u003e\u003cp\u003eBut now Memory wants to end at the origin. To do this, he has a special trident. This trident can replace any character in \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e\u003c/span\u003e with any of \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eL\u003c/span\u003e\u0027, \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eR\u003c/span\u003e\u0027, \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eU\u003c/span\u003e\u0027, or \u0027\u003cspan class\u003d\"tex-font-style-tt\"\u003eD\u003c/span\u003e\u0027. However, because he doesn\u0027t want to wear out the trident, he wants to make the minimum number of edits possible. Please tell Memory what is the minimum number of changes he needs to make to produce a string that, when walked, will end at the origin, or if there is no such string.\u003c/p\u003e\n记忆从原点开始在二维平面上行走。他得到了一个字符串 s ,上面有他的运动方向:\n\u003c/p\u003e\n\u0027L\u0027表示他应该向左移动一个单位。\u003c/p\u003e\n一个\"R\"表示他应该向右移动一个单位。\u003c/p\u003e\n一个\"U\"表示他应该向上移动一个单位。\u003c/p\u003e\n\u0027D\u0027表示他应该向下移动一个单位。\u003c/p\u003e\n但是现在 Memory 想要在原点结束。为此,他有一个特殊的三叉戟。这个三叉戟可以用\u0027L\u0027、\u0027R\u0027、\u0027U\u0027或\u0027D\u0027中的任意一个替换 s 中的任意字符。但是,由于他不想磨损三叉戟,他希望尽可能减少编辑次数。请告诉 \"记忆\",他至少需要做多少次修改,才能得到一个在行走时以原点为终点的字符串,或者是否不存在这样的字符串。"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe first and only line contains the string \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e\u003c/span\u003e (\u003cspan class\u003d\"tex-span\"\u003e1 ≤ |\u003ci\u003es\u003c/i\u003e| ≤ 100 000\u003c/span\u003e)\u0026nbsp;— the instructions Memory is given.\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eIf there is a string satisfying the conditions, output a single integer\u0026nbsp;— the minimum number of edits required. In case it\u0027s not possible to change the sequence in such a way that it will bring Memory to to the origin, output \u003cspan class\u003d\"tex-font-style-tt\"\u003e-1\u003c/span\u003e.\u003c/p\u003e"}},{"title":"Sample 1","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003eRRU\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e-1\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Sample 2","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003eUDUR\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e1\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Sample 3","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003eRUUR\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e2\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"Note","value":{"format":"HTML","content":"\u003cp\u003eIn the first sample test, Memory is told to walk right, then right, then up. It is easy to see that it is impossible to edit these instructions to form a valid walk.\u003c/p\u003e\u003cp\u003eIn the second sample test, Memory is told to walk up, then down, then up, then right. One possible solution is to change \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003es\u003c/i\u003e\u003c/span\u003e to \"\u003cspan class\u003d\"tex-font-style-tt\"\u003eLDUR\u003c/span\u003e\". This string uses 1 edit, which is the minimum possible. It also ends at the origin.\u003c/p\u003e"}}]}