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.
s = input()
if s.count("AB") > 1 or s.count("BA") > 1:
    print("YES")
else:
    n = len(s)
    for x in range(n - 2):
        if s[x] == 'A' and s[x + 1] == 'B' and s[x + 2] == 'A':
            print("NO")
            break
        if s[x] == 'B' and s[x + 1] == 'A' and s[x + 2] == 'B':
            print("NO")
            break
    else:
        if "AB" in s or "BA" in s:
            print("YES")
        else:
            print("NO")