using System;

public class Program

{

    public static void Main()

    {

        double r, chu_vi, dien_tich;

            double PI = 3.14;

            Console.Write("Nhap ban kinh duong tron: ");

            r = Convert.ToDouble(Console.ReadLine());

            chu_vi = 2 * PI * r;

            Console.WriteLine("\nChu vi duong tron la: {0}", chu_vi);

            dien_tich = PI * r * r;

            Console.WriteLine("Dien tich duong tron la: {0}", dien_tich);

        Console.Read();

    }

}