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()

# Search for "AB" substring
AB_POSITION = s.find("AB")

# Search for "BA" substring
BA_POSITION = s.find("BA")

# Check if both substrings are found and their positions are non-overlapping
if AB_POSITION != -1 and ba_pos != -1 and abs(AB_POSITION - BA_POSITION) > 1:
    print("YES")
else:
    # Check if the positions of the substrings are reversed
    if BA_POSITION != -1 and s.find("AB", BA_POSITION + 2) != -1:
        print("YES")
    elif AB_POSITION != -1 and s.find("BA", AB_POSITION + 2) != -1:
        print("YES")
    else:
        print("NO")

  	 		 	   		 				   						 	 	