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_substrings(s):
    # Check if "AB" and "BA" exist in the string, non-overlapping
    if "AB" in s and "BA" in s[s.index("AB")+2:]:
        return "YES"
    if "BA" in s and "AB" in s[s.index("BA")+2:]:
        return "YES"
    return "NO"

# Read the input string
s = input()

# Call the function to check substrings
result = check_substrings(s)

# Print the result
print(result)
