package yukicoder;

import java.util.Scanner;

public class Yuki166 {
	
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int h = scan.nextInt();
		int w = scan.nextInt();
		int n = scan.nextInt();
		int k = scan.nextInt();
		scan.close();
		
		int mas = (h * w) % n;
		// System.out.println(mas);

		if( mas - k == 0){
			System.out.println("YES");
		} else {
			System.out.println("NO");
		}
	}	
}