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 has_non_overlapping_AB_BA(s):
    if "AB" in s:
        s1 = s.replace("AB", "--", 1)
        if "BA" in s1:
            return "YES"
    if "BA" in s:
        s2 = s.replace("BA", "--", 1)
        if "AB" in s2:
            return "YES"
    return "NO"

# Input
s = input()

# Output
print(has_non_overlapping_AB_BA(s))

	 	  		 		 			  		  	 	  	 			