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

class Program
{
    public void Solve()
    {
        string[] HWNK = Console.ReadLine().Split(' ');
        long H = long.Parse(HWNK[0]);
        long W = long.Parse(HWNK[1]);
        long N = long.Parse(HWNK[2]);
        long K = long.Parse(HWNK[3]);

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

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

    static void Main()
    {
        var solver = new Program();
        solver.Solve();
    }
}