using System;

public class Hello
{
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var h = long.Parse(line[0]);
        var w = long.Parse(line[1]);
        var n = long.Parse(line[2]);
        var k = long.Parse(line[3]);
        Console.WriteLine(h * w % n == k ? "YES" : "NO");
    }
}