def resolve():

    s=list(eval(input()))

    if len(set(s))==1:

        print('No')

    else:

        print('Yes')



resolve()
import sys

sys.setrecursionlimit(10 ** 5 + 10)

def input(): return sys.stdin.readline().strip()



def resolve():

    s = str(eval(input()))

    if len(set(s))==1:

        print('No')

    else:

        print('Yes')

    

    

resolve()
def resolve():
    s = list(eval(input()))
    if len(set(s)) == 1:
        print("No")
    else:
        print("Yes")


resolve()

import sys

sys.setrecursionlimit(10**5 + 10)


def input():
    return sys.stdin.readline().strip()


def resolve():
    s = str(eval(input()))
    if len(set(s)) == 1:
        print("No")
    else:
        print("Yes")


resolve()

+import sys + +sys.setrecursionlimit(10**5 + 10) + + +def input(): +    return sys.stdin.readline().strip() + + -    s = list(eval(input())) +    s = str(eval(input()))