import java.util.Scanner;

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

		}
	}
}