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

using System.Numerics;

namespace yukikoda
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] s = Console.ReadLine().Split();

            BigInteger a = BigInteger.Parse(s[0]);
            BigInteger b = BigInteger.Parse(s[1]);
            BigInteger c = BigInteger.Parse(s[2]);
            BigInteger d = BigInteger.Parse(s[3]);

            Console.WriteLine(a * b * c % d);
        }
    }
}