using System;
using System.Collections.Generic;
using System.Linq;

class Magatro
{
   static void Main() {
        long h, w, n, k;
        long[] q = Console.ReadLine().Split(' ').Select(s => long.Parse(s)).ToArray();
        h = q[0];
        w = q[1];
        n = q[2];
        k = q[3];
        k %= n;
        if (((h%n) * (w%n)) % n == k)
        {
            Console.WriteLine("YES");
        }
        else
        {
            Console.WriteLine("NO");
        }
    }
}