#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <iomanip>
#include <algorithm>
#include <map>
using namespace std;
using ll = long long;
constexpr ll M = 1e9+7;
constexpr double eps = 1e-10;

int main() {
    ll H, W, N, K;
    cin >> H >> W >> N >> K;
    ll t = H*W % N;

    if((t == 0 ? N : t) == K) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }
}