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 'AB' in s and 'BA' in s:
    # Find the first occurrence of "AB" and the first occurrence of "BA" after the "AB"
    ab_index = s.find('AB')
    ba_index = s.find('BA', ab_index + 2)

    # Check if the substrings are non-overlapping
    if ba_index != -1 and ba_index != ab_index + 1:
        print('YES')
    else:
        # Find the first occurrence of "BA" and the first occurrence of "AB" after the "BA"
        ba_index = s.find('BA')
        ab_index = s.find('AB', ba_index + 2)

        # Check if the substrings are non-overlapping
        if ab_index != -1 and ab_index != ba_index + 1:
            print('YES')
        else:
            print('NO')
else:
    print('NO')
