#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    long long h, w, n, k, r;
    cin >> h >> w >> n >> k;
    r = (h*w)%n;
    cout << ((r == k || (r == 0 && n == k)) ? "YES" : "NO") << endl;
}