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

int main()
{
long long H;
long long W;
long long N;
long long K;

	cin >> H;
	cin >> W;
	cin >> N;
	cin >> K;

	H %= N;
	W %= N;
	H *= W;
	H %= N;
	K %= N;
	if( H == K )
		cout << "YES" << endl;
	else
		cout << "NO" << endl;

	return 0;
}