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()

# Find the indices of "AB" and "BA" in the string
ab_index = s.find("AB")
ba_index = s.find("BA")

# Check if both substrings are present and non-overlapping
if ab_index != -1 and ba_index != -1 and ab_index + 1 < ba_index:
    print("YES")
else:
    # Swap "AB" and "BA" and check again
    ba_index = s.find("BA", ab_index + 2)
    ab_index = s.find("AB", ba_index + 2)
    
    if ab_index != -1 and ba_index != -1 and ba_index + 1 < ab_index:
        print("YES")
    else:
        print("NO")

  		  			       	 	 		  	  		