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.
import re

st = input()
ab_match = re.search(r'AB', st)
ba_match = re.search(r'BA', st)

if ab_match and ba_match:
    # Check if the absolute difference of the start positions is not 1
    if abs(ab_match.start() - ba_match.start()) > 1:
        print('YES')
    else:
        print('NO')
else:
    print('NO')
