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.
s = input()
if s.count('AB') + s.count('BA') - s.count('ABA') - s.count('BAB') - 1 and s.find('AB') + 1 and s.find('BA') + 1:print("YES")
else:print("NO")