using System;

public class Program

{

    public static void Main()

    {

        string input;

        int radius;

        double area;

        // input

        Console.Write("Please enter the radius");

        input = Console.ReadLine();

        radius = int.Parse(input);

        // processing

        area = Math.PI * radius * radius;

        //output

        Console.WriteLine("The area is {0}", area.ToString("#.00"));

    }

}