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_BA(s):
    # Check if "AB" appears in the string
    if "AB" in s:
        # Look for "BA" in the remaining part of the string
        remaining = s.replace("AB", "", 1)
        if "BA" in remaining:
            return "YES"

    # Check if "BA" appears in the string
    if "BA" in s:
        # Look for "AB" in the remaining part of the string
        remaining = s.replace("BA", "", 1)
        if "AB" in remaining:
            return "YES"

    # If both checks failed, return "NO"
    return "NO"

# Read input
s = input()

# Call the function and print the result
result = contains_AB_BA(s)
print(result)

  					    	 	  			 	 	  	 	  	