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

class prog
{
  static void Main()
  {
    var a=Console.ReadLine().Split().Select(int.Parse).ToArray().ValidateArray(x=>1<=x&&x<=1000000000);
    a.Validate(x=>x.Length==4);
    Console.ReadLine().Validate(x=>x==null);
    var v=a[0];
    v*=a[1];
    v%=a[3];
    v*=a[2];
    v%=a[3];
    Console.WriteLine(v);
  }
}

static public class Validator
{
    static public T Validate<T>(this T input, Func<T, bool> f)
    {
        if (!f(input))
            throw new Exception("invalid input");
        return input;
    }
    static public T[] ValidateArray<T>(this T[] input, Func<T, bool> f)
    {
        foreach (var x in input)
            if (!f(x))
                throw new Exception("invalid input");
        return input;
    }
}