using System;

public class Program

{

    public static void Main()

    {

        // kruh

        Console.WriteLine("Zadej stranu r");

        int r = System.Int32.Parse(Console.ReadLine());

        double π = 3.14159265359;

        double obvodct = π*2*r;

        double obsahct = π*r*r;

        Console.WriteLine("Obvod kruhu je "+obvodct);

        Console.WriteLine("Obsah kruhu je "+obsahct);

​

    }

}