#include <iostream>
#include <vector>
#include <sstream>
using namespace std;


int main()
{
	string in;
	int temp;
	vector<int> v;

	getline(cin,in);
	stringstream ss(in);
	
	while(!ss.eof()){
		ss>>temp;
		v.push_back(temp);
		ss.ignore();
	}

	int w,n,k;
	long h;
	h = v.at(0);
	w = v.at(1);
	n = v.at(2);
	k = v.at(3);
	h *= w;
	h %= n;
	if(h == 0 && n == k){
		cout<<"YES"<<endl;
	}else if(h == 0){
		cout<<"NO"<<endl;
	}else if(h == k){
		cout<<"YES"<<endl;
	}else{
		cout<<"NO"<<endl;
	}
	return 0;
}