ls_1 = list(map(int, input().split('.')))
ls_2 = list(map(int, input().split('.')))

for i in range(len(ls_1)):
    if ls_1[i] > ls_2[i]:
        print('YES')
        break
    elif ls_1[i] < ls_2[i]:
        print('NO')
        break
    else:
        continue
else:
    print('YES')