using System;

public class Program

{

    public static void Main()

    {

        Console.Write("Въведете радиус: ");

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

        double Area=Math.PI*r*r;

        double P=2*Math.PI*r;

        Console.WriteLine( "Area="+Area);

        Console.WriteLine( "Perimeter="+P);

​

​

    }

}