import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

a, b = na()
for i in range(12):
    x = a // (10 ** i) % 10
    y = b // (10 ** i) % 10
    if x < y:
        No()
        break
else:
    Yes()