def main():

    S = eval(input())

    S = set(S)

    if len(S) == 1:

        print("No")

    else:

        print("Yes")





if __name__ == '__main__':

    main()

def main():

    S = eval(input())

    if len(set(s for s in S)) == 1:

        print("No")

    else:

        print("Yes")





if __name__ == '__main__':

    main()

def main():
    S = eval(input())
    S = set(S)
    if len(S) == 1:
        print("No")
    else:
        print("Yes")


if __name__ == "__main__":
    main()

def main():
    S = eval(input())
    if len(set(s for s in S)) == 1:
        print("No")
    else:
        print("Yes")


if __name__ == "__main__":
    main()

-    S = set(S) -    if len(S) == 1: +    if len(set(s for s in S)) == 1: