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):
    # Search for "AB" in the string
    if "AB" in s:
        # Check if "BA" is present after the "AB"
        if "BA" in s[s.index("AB") + 2:]:
            return "YES"
    
    # Search for "BA" in the string
    if "BA" in s:
        # Check if "AB" is present after the "BA"
        if "AB" in s[s.index("BA") + 2:]:
            return "YES"
    
    return "NO"

# Read input string
s = input().strip()

# Check if the input string contains the required substrings
result = contains_AB_BA(s)
print(result)