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.
a=input()
count1=a.count("AB")
a=a.replace("AB","")
count2=a.count("BA")
if(count1+count2>1):
    print("YES")
else:
    print("NO")