System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace SoloLearn

{

    class Program

    {

        static void Main(string[] args)

        {

        Console.Write("a=: ");

int a= Convert.ToInt32(Console.ReadLine());

int p=4*a;

    Console.WriteLine(p);

        }

    }

}