using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        string[] HWNK = Console.ReadLine().Split(' ');
        int H = int.Parse(HWNK[0]);
        int W = int.Parse(HWNK[1]);
        int N = int.Parse(HWNK[2]);
        int K = int.Parse(HWNK[3]);

        int loser = H * W % N;
        if (loser == 0) { loser = N; }

        Console.WriteLine(loser == K ? "YES" : "NO");
    }
}