#include <iostream>
using namespace std;
int main() {
	long long H, W, N, K;
	cin >> H >> W >> N >> K;
	if (K == ((H*W) % N)) {
		cout << "YES" << endl;
	}
	else {
		if (K == N && (H*W) % N == 0) {
			cout << "YES" << endl;
			return 0;
		}
		cout << "NO" << endl;
	}
	return 0;
}