CodeForces 550A Two Substrings_牛客题霸

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

ABA<br />BACFAB<br />AXBYBXA<br />

输出

NO<br />YES<br />NO<br />

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".