using System;

​

namespace TenSec

{

public class Program

{

    public static void Main()

    {

        double r, S;

        Console.Write("r = ");

        r = double.Parse(Console.ReadLine());

         S = 4 * Math.PI * Math.Pow(r, 2);

        Console.WriteLine("S = {1}", r, S);

    }

}

}