#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <climits>
#include <vector>
#include <numeric>
#include <complex>
#include <map>
#include <bitset>
using namespace std;

#define __int64 long long
#define long __int64
#define REP(i,a,b) for(int i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
const int Vecy[4] = {0,-1,0,1};
const int Vecx[4] = {1,0,-1,0};


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