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()
s = s.split('AB')
new_s = "AB"
for a in s:
    if "BA" in a:
        print("YES")
        break
    else:
        print("NO")
        break