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()
abs_pos = [m.start() for m in re.finditer('AB', s)]
b_pos = [m.start() for m in re.finditer('BA', s)]

found = False

for num1 in abs_pos:
    for num2 in b_pos:
        if abs(num1 - num2) > 1:
            found = True
            break
    if found:
        break

if found:
    print('YES')
else:
    print('NO')

 	 		 	 		 	  	  			 	 	 		 	 	