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.
s1=input()
p="AB"
q="BA"
if p in s1:
    x=s1.replace(p,"")
else:
    print("NO")
if q in x:
    print("YES")
else:
    print("NO")
