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() 
sAB = s.find("AB")
sBA = s.find("BA")
 
if sAB != -1 and sBA != -1 and abs(sAB - sBA) > 1:
    print("YES")
else:
    # Find the first occurrence of "AB" and search for "BA" after that position
	if "AB" in s and "BA" in s[s.index("AB") + 2:]:
		print("YES")
		exit()
	# Find the first occurrence of "BA" and search for "AB" after that position
	if "BA" in s and "AB" in s[s.index("BA") + 2:]:
		print("YES")
		exit()
	else:
		print("NO")