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1767: [NewOJ Contest 8] QAQ

内存限制：256 MB 时间限制：1 S 标准输入输出
题目类型：传统 评测方式：文本比较 上传者：
提交：59 通过：28
提交提交记录统计

题目描述

给你一个长度为2000的字符串S，只包含字符A和Q，请求出存在多少个长度为3的子序列是QAQ。
即存在多少种情况满足S[i]='Q',S[j]='A',S[k]='Q'，i<j<k。

输入格式

无输入，给定字符串在样例输入中。

输出格式

输出一个数字表示答案。

输入样例 复制 

QQAAQAQQAQQQAQAQAQQQQQQQAAQQQQQQQQQAQAAQQQQQQQQAQAQQAQQAQQAAAQQQQAAQAAQQQQAQQQQQQQQAQQAQQAQQQAQAQQQQQQAQQQQQQQQQQAQQQQQQAQQQQQQAQAQAQAAAQQAQAQQQQQAQQQQAQAQQQQQQAQQQQQAQQQAQQAQQQQQAAQQAQQQQAQQAQAQQQQAAQQQQQQAQAQQAQQAQQAQQAQAQQQQQQQQQQQAAQQAAQQAQQQQAAQQQQQQQAQQQAQQQQQQQAQQQAQQQQQQAQQQQQAAAQAAAQQAQQQQQQQAQQAQAAQAQAQQQAAAAAAQAAQQAQAQAQQQAQAQQQAQAQQQQQQAAQAAAQQAAQQAQQQQQQQQQQQAQAQQQAQQQQAQAQQQQQQAQQAQQAQQAQQQQQAQAQQAAAQQQAQQQQQQAQQQAQQQQQAAQAQQQAAQQAQQAQAQAAQAQAQAQQAAQAQAQAQQQAQQQAAQAQQQAAQAQQAQQQAAQAAAAQAAQQQQAQQQAQAQQQAAAAQQQQAQAAQQQQAAQQQQQAQAQAAQAAAQQQQQAQQAQQQAQQQQQQQAQAAQQQQQAQAAQQQQQQAQQAQQQQAAQQQQQQQAAQAAQAQQQQAQAQQQQAQAQQQQAQQQQQAQAQQQAQAQQQQQAQAQQAAQQQAQQQQQQAAQAQAQQQQAAQQQAQQQQAAQAQQAQQAAAAQQAQQQQQAQQAAQQQQQQAQQAQQAQQAQQQAAQQQQQQQQAQQQQQQAQAQAQQAQAAQQQQQQQQQAQQQQAQQQAAQQQQQQQAQQQAQAAQQQQQQAQAAQQAAQQQQAAQQAAQQQQQQQQQAQQAQAQAAAQQAQQAQQAQAAQQQQQQAQAAQAAQQQQAQQQAQQQAQQAAAAQQAQQQQQAQQAQAQAQQQQQQAQQQQAQQAQQQQQQQAQQQQAAQAQQAQAQQQQQQQQQQQQAQAAQAAAAAQAQQQAQAQAQQAAQAQAQAAQQQAQQQQAQQQQAQQQQQAQAQQQQAQAQQQQAQAQAQQAQQAQAAQQAQAQAQAAQQAAQQQQAAAQQQQAQQQQAQQQQAQQQAQAAAQQAQQQAQAQQQQQQQQAQAQAQQQAAQAAQQQQQAAAQAQAQQQQQQAQQQQAQQQAAQQAQQQQQAQQQQQQQQQQAAQQAQQAQAQQQQAQAQAQQQAQAQQAQQQQQAAQQAQAAAAAQQAQQQQQQAQQAAQQAAQQAAQQQQAAQAAQQQAAQAQQQQQQAQAQQQQQQQQQQQAQQQAQAQAQAAQAQQQAQQQQQQQAAAAAQQQAQQQQAQQQAQAAQQAQQAQQAAQAQAAAQQQAQQQQQQQAQAQQQAQQQQQQAQQQAAQQQQQQQQAQQQQAQAAQQQQQQQQQAQQQAQAQQQQQAAAQQQQQQAQQQAQAAAAQAQQQQQQQQAQAQQQQAAQQQQQAQQAQQQQQQQQAQAQQAQQAAAQQQAQAAAAQQAAQQQAAQQQQAQQQQQQQQQQQQAQQQAQQQQQQQAQQQQQQQAQQAAQQAQQQQQAAAQQAQAAQQQAQAQQAQAQQQQAQAQAQAQQAQAQAQAQQAQQQQQQAQQQAAAQAQQAQQQAAQAQQQQQQQQQQQQAQQQQQAQQQQQQAQAQAAAAAQQQQAAAAAAAQQQQQQAQQQAQAQQQAQAQAAQQQAQQQAQQQAAQQAQQAQQAQQAQQQAAAAQQQQQQQQAQQQQQQAQAQQQQQQQQAAAAAAQAQQQQAAAQQAQAQQQQQAQQAAQQQAAQAAQAQAQAQQAAQAQAQAAAQQQAAQQQQQQAQQQAAQAQQQQAQQAQQQAQAAQQQAQQQQQQAQQAAQAQAQAAQAQQAQQQQAQAQQAQQQAAAQQQQQQQQAAQQQQQQQAQQQQQAQAQAAAAAAAQQAQQQQQQQQAQQQAAQQAAQQAQAQQAQAQAQAQAAQQQQQQQAAQQQQQQQQQQAQQQQAQQQQQAQQQQQQQQQAQQQQAQQQAAQQAAAQAQQQQQAAAQQAQAQQAQAAQQQQQQQA

输出样例 复制