#include <bits/stdc++.h>
using namespace std;

int H, W, N, K;
void input() { cin >> H >> W >> N >> K; }

void solve() {
  string ans = "YES";
  int chk = H * W % N;
  if (chk == 0) chk = N;
  if (chk != K) ans = "NO";
  cout << ans << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  input();
  solve();
  getchar();
}