import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long H = sc.nextLong();
    long W = sc.nextLong();
    long N = sc.nextLong();
    long K = sc.nextLong();
    String ans = "NO";
    if(((H * W) % N) == K) ans = "YES";
    if(((H * W) % N) == 0 && K == N) ans = "YES";
    System.out.println(ans);
  }
}