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.
a=input()
count=0
for i in range(len(a)-2):
    if (a[i]=='A' and a[i+1]=='B' and a[i+2] !='A') :
        count+=1
    elif a[i]=='B' and a[i+1]=='A' and a[i+2] !='B':
        count+=1
    print(a[i])
    print(a[i+1])
if count>2:
    print('YES')
else:
    print('NO')