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<sup class="upper-index">5</sup> consisting of uppercase Latin letters.
from sys import stdin


def solve():
    s = input()
    if ('BA' in s[s.find('AB') + 2:] or 'AB' in s[s.find('BA') + 2:]) and 'BA' in s and 'AB' in s:
        print('YES')
    else:
        print('NO')


if __name__ == '__main__':
    solve()
