Two Substrings

给你一个字符串 $S$（$1 \leq |S| \leq 10^4$），判断 $S$ 中是否有不相交的 $BA$，$AB$ 这两个子串。如果存在，输出 `Yes`，否则输出 `No`。

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).

The only line of input contains a string $ s $ of length between $ 1 $ and $ 10^{5} $ consisting of uppercase Latin letters.

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

ABA

NO

BACFAB

YES

AXBYBXA

NO

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".