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.
def contains_ab_and_ba(s):
    if "AB" in s:
        if "BA" in s[s.index("AB") + 2:]:
            return "YES"
    if "BA" in s:
        if "AB" in s[s.index("BA") + 2:]:
            return "YES"
    return "NO"

s = input().strip()
print(contains_ab_and_ba(s))