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()
if not(s.count("AB")) or not(s.count("BA")):
    print("NO")
elif s.count("ABABA") or s.count("BABAB"):
    print("YES")
else:
    final=" "
    for i in s:
        if (i=="A" or i=="B") and i!=final[-1]:
            final+=i
        else:
            final+=" "
            if (i=="A" or i=="B"):
                final+=i
    lis=list(filter(lambda x:x!="A" and x!="B" and x!=" ",final.split()))
    ab=0;ba=0;extra=0
    for i in lis:
        if i=="AB":
            ab+=1
        elif i=="BA":
            ba+=1
        else:
            extra+=1
    if extra+min(1,ab)+min(ba,1)>1:
        print("YES")
    else:
        print("NO")