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.
def main():
    s = input()
    kol = 0
    kol2 = 0
    kol = s.find('BA', kol)
    kol2 = s.find("AB", kol2+2)
    #print(kol2)
    if kol != -1 and kol2 != -1:
            print("YES")
            return 0
    else:
        kol = 0
        kol2 =  0
        kol2 = s.find("AB", kol2)
        kol = s.find("BA",kol2+2)
        if kol != -1 and kol2 != -1:
            print('YES')
            return 0
        else:
            print('NO')
            return 0
main()
