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 check(s: str) -> bool:
    index_ab = s.find("AB")
    index_ba = s.find("BA")

    if index_ab == -1 and index_ba == -1:
        return False

    if index_ab >= 0 and index_ba >= 0:
        return abs(index_ab - index_ba) > 2

    return False

if check(input()):
    print('YES')
else:
    print('NO')
		  	 			  	       	 		  			 	