#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define all(a) (a).begin(),(a).end()
#define dunk(a) cout << (a) << endl
using namespace std;
typedef long long ll;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	ll h, w, n, k;
	cin >> h >> w >> n >> k;

	ll res = h * w % n;

	if (res == k % n) puts("YES");
	else puts("NO");

	return 0;
}