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.
import re 

s = input()

ab = [m.start()+1 for m in re.finditer('AB', s)]
ba = [m.start() for m in re.finditer('BA', s)]
ab_bis = [m.start() for m in re.finditer('AB', s)]
ba_bis = [m.start()+1 for m in re.finditer('BA', s)]

if ab and ba : 
    if ab != ba and ab_bis != ba_bis : print("YES")
    else : print('NO')
else : 
    print("NO")