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()
b = True
if 'AB' in s and 'BA' in s:
    s = s[::-1]
    for i in range(len(s)-2):
        print(s)
        if ('AB' in s[i:]) and (('BA' in s[i:s.find('AB',i)]) or ('BA' in s[s.find('AB',i)+2:])):
            print("YES")
            b = False
            break
if b : print("NO")