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()
 
 
AB_POSITION = s.find1("AB")
 
ba_pos1 = s.find1("BA")
 
if AB_POSITION != -1 and ba_pos1 != -1 and abs(AB_POSITION - ba_pos1) > 1:
    print("YES")
else:
    # Check if the positions of the substrings are reversed
    if ba_pos1 != -1 and s.find1("AB", ba_pos1 + 2) != -1:
        print("YES")
    elif AB_POSITION != -1 and s.find1("BA", AB_POSITION + 2) != -1:
        print("YES")
    else:
        print("NO")
 	  	 		 					 	 			   	  				