import java.io.*;
import java.util.*;
import java.math.*;

class Main166 {
	
	public static void out (Object out) {
		System.out.println(out);
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		String[] line = br.readLine().split(" ");
		int h = Integer.parseInt(line[0]);
		int w = Integer.parseInt(line[1]);
		long n = Long.parseLong(line[2]);
		long k = Long.parseLong(line[3]) % n;
		
		System.out.println((h * w) % n == k ? "YES" : "NO");
	}
}