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

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

    cin >> H >> W >> N >> K;
    masu = H*W;

    if(masu%N == K){
        cout << "YES" << endl;
    }else if(masu%N == 0 && N == K){
        cout << "YES" << endl;
    }else{
        cout << "NO" << endl;
    }

    return 0;
}