Two Substrings
时间限制:C/C++/Rust/Pascal 2秒,其他语言4秒
空间限制:C/C++/Rust/Pascal 256 M,其他语言512 M
64bit IO Format: %lld

题目描述

You are given string s. Your task is to determine if the given string s contains two non-overlapping substrings "AB" and "BA" (the substrings can go in any order).

输入描述:

The only line of input contains a string s of length between 1 and 105 consisting of uppercase Latin letters.

输出描述:

Print "YES" (without the quotes), if string s contains two non-overlapping substrings "AB" and "BA", and "NO" otherwise.

示例1

输入

复制
ABA

输出

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NO
示例2

输入

复制
BACFAB

输出

复制
YES
示例3

输入

复制
AXBYBXA

输出

复制
NO

备注:

In the first sample test, despite the fact that there are substrings "AB" and "BA", their occurrences overlap, so the answer is "NO".

In the second sample test there are the following occurrences of the substrings: BACFAB.

In the third sample test there is no substring "AB" nor substring "BA".