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()
setAB= []
setBA= []
flag = True
for i in range(0,len(a)-1):
    if(a[i:i+2]=='AB'):
        setAB.append(i)
    if(a[i:i+2]=='BA'):
        setBA.append(i)
if(len(setAB)==0 or len(setBA)==0):
    print("No")
    quit()

for i in setAB:
    for j in setBA:
        if(j!=i-1 and j!=i+1):
            print("Yes")
            quit()
print("No")


