#include <bits/stdc++.h>

inline long nextInt(void) {
  long temp;
  std::cin >> temp;
  return temp;
}

int main() {

  long H, W, N, K;
  long size;

  std::cin >> H >> W >> N >> K;

  size = (H * W) % N;

  if( size == K || (size == 0 && K == N) ) {
    std::cout << "YES" << std::endl;
  }
  else {
    std::cout << "NO" << std::endl;
  }
  
  
  return 0;
}