#include <iostream>
#include <vector>
#include <algorithm>
#include <unordered_set>

using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    long long h, w, n, k;
    cin >> h >> w >> n >> k;

    k = n == k ? 0 : k;
    if (h * w % n == k) cout << "YES" << endl;
    else cout << "NO" << endl;

    return 0;
}