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

namespace yukicoder
{
    class yc
    {
        static void Main()
        {
            string[] str = Console.ReadLine().Split();
            int H = int.Parse(str[0]);
            int W = int.Parse(str[1]);
            int N = int.Parse(str[2]);
            int K = int.Parse(str[3]);

            if (K == N && H * K % N == 0)
                Console.WriteLine("YES");
            else if (H * W % N == K) 
                Console.WriteLine("YES");
            else 
                Console.WriteLine("NO");
        }
    }
}