#include <bits/stdc++.h>
using namespace std;

string A, B;

int main() {
	cin >> A >> B;
	int N = A.size();
	int M = B.size();
	for (int i = 1; i <= min(N, M); i++) {
		if (A[N - i] < B[M - i]) {
			cout << "No" << endl;
			return 0;
		}
	}
	cout << "Yes" << endl;
	return 0;
}