#include <bits/stdc++.h>

using namespace std;

#define LL long long

int main() {
    LL h, w, n, k;
    cin >> h >> w >> n >> k;

    LL hh = h % n, ww = w % n;
    if ((hh * ww - k) % n == 0) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }
    return 0;
}