def main():
    A0 = tuple(map(int, input().split('.')))
    A1 = tuple(map(int, input().split('.')))

    for i, j in zip(A0, A1):
        if i < j:
            print('NO')
            break
        elif i > j:
            print('YES')
            break
    else:
        print('YES')

main()