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();
        long z = H*W%N;
        
        if(z==K){
            System.out.println("YES");
        }else if(z==0 && K==N){
            System.out.println("YES");
        }else{
            System.out.println("NO");
        }
    }
}