A,B = input().split()
A_num = int(A)
B_num = int(B)

A = list(map(int,reversed(list(A))))
B = list(map(int,reversed(list(B))))

for a,b in zip(A,B):
    if a < b:
        print("No")
        exit()

if A_num < B_num:
    print("No")

print("Yes")