#include<iostream>
#include<stdio.h>

using namespace std;

int main(){
    long long int h, w, n, k;
    cin>> h>> w>> n>> k;

    h %= n;
    w %= n;
    long long int masu = h*w;
    masu %= n;

    if(k==masu){
        cout<< "YES"<< endl;
    }else if(masu==0 && k==n){
        cout<< "YES"<< endl;
    }else{
        cout<< "NO"<< endl;
    }
    return 0;
}