{"trustable":true,"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\u003e\"QAQ\"是一个表示哭泣表情的词语。想象一下,\"Q\"代表眼睛有泪水,\"A\"代表嘴巴。\u003c/p\u003e\u003cp\u003e现在,Diamond给了Bort一个仅包含大写英文字母且长度为\u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e的字符串。字符串中有很多个\"QAQ\"(Diamond真是太可爱了!)。\u003c/p\u003e\u003ccenter\u003e \u003cimg class\u003d\"tex-graphics\" height\u003d\"259px\" src\u003d\"CDN_BASE_URL/31d685c32dbc614f3f8e1cbdff11eb08?v\u003d1707987973\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\" width\u003d\"341px\"\u003e \u003cspan class\u003d\"tex-font-size-tiny\"\u003e插图由猫屋提供 https://twitter.com/nekoyaliu\u003c/span\u003e \u003c/center\u003e\u003cp\u003eBort想知道Diamond给出的字符串中有多少个子序列\"\u003cspan class\u003d\"tex-font-style-tt\"\u003eQAQ\u003c/span\u003e\"。请注意,字母\"\u003cspan class\u003d\"tex-font-style-tt\"\u003eQAQ\u003c/span\u003e\"不必连续出现,但字母的顺序必须完全一致。\u003c/p\u003e"}},{"title":"输入","value":{"format":"HTML","content":"\u003cp\u003e仅包含长度为\u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e(\u003cspan class\u003d\"tex-span\"\u003e1 ≤ \u003ci\u003en\u003c/i\u003e ≤ 100\u003c/span\u003e)的字符串一行。保证字符串只包含大写英文字母。\u003c/p\u003e"}},{"title":"输出","value":{"format":"HTML","content":"\u003cp\u003e输出一个整数\u0026nbsp;— 字符串中\"\u003cspan class\u003d\"tex-font-style-tt\"\u003eQAQ\u003c/span\u003e\"子序列的数量。\u003c/p\u003e"}},{"title":"示例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\u003eQAQAQYSYIOIWIN\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e4\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}},{"title":"示例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\u003eQAQQQZZYNOIWIN\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e3\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e"}},{"title":"注意","value":{"format":"HTML","content":"\u003cp\u003e在第一个示例中,字符串中有\u003cspan class\u003d\"tex-span\"\u003e4\u003c/span\u003e个子序列\"\u003cspan class\u003d\"tex-font-style-tt\"\u003eQAQ\u003c/span\u003e\": \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eQAQ\u003c/span\u003eAQYSYIOIWIN\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eQA\u003c/span\u003eQA\u003cspan class\u003d\"tex-font-style-bf\"\u003eQ\u003c/span\u003eYSYIOIWIN\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003e\u003cspan class\u003d\"tex-font-style-bf\"\u003eQ\u003c/span\u003eAQ\u003cspan class\u003d\"tex-font-style-bf\"\u003eAQ\u003c/span\u003eYSYIOIWIN\u003c/span\u003e\", \"\u003cspan class\u003d\"tex-font-style-tt\"\u003eQA\u003cspan class\u003d\"tex-font-style-bf\"\u003eQAQ\u003c/span\u003eYSYIOIWIN\u003c/span\u003e\"。\u003c/p\u003e"}}]}