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

class Program
{
    public void Solve()
    {
        decimal[] ABCD = Console.ReadLine().Split(' ').Select(s => decimal.Parse(s)).ToArray();
        Console.WriteLine(ABCD[0] * ABCD[1] * ABCD[2] % ABCD[3]);
    }

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