#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 5000000000000000000



int main(){	
	
	long long H,W,N,K;
	cin>>H>>W>>N>>K;
	
	H*=W;
	H%=N;
	if(H==K%N)cout<<"YES"<<endl;
	else cout<<"NO"<<endl;
	
	return 0;
	
}