#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <list>
#include <functional>
#include <queue>
#include <map>
#include <iterator>
#include <iomanip>
#include <complex>
#include <cctype>
using namespace std;

using ull = unsigned long long;
using ll = long long;


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

  if(h*w % n == k %n)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}