#include <iostream>
using namespace std;


int main() {
    int h,w,n,k;
    cin >> h >> w >> n >> k;
    if((h*w)%n == k )cout << "YES" << endl;
    else if((h*w)%n == 0 && n == k)cout << "YES" << endl;
    else cout << "NO" << endl;
return 0;
}