Problem:
Circle

Write a program which calculates the area and circumference of a circle for given radius r.

Input

A real number r is given.

Output

Print the area and circumference of the circle in a line. Put a single space between them. The output should not contain an absolute error greater than 10-5.

Constraints

0 < r < 10000

Sample Input 1

2

Sample Output 1

12.566371 12.566371

Sample Input 2

3

Sample Output 2

28.274334 18.849556

Solution in C# (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Collections;
//using System.Linq;
//using System.Text;
//using System.Threading.Tasks;

//namespace _1_A
//{
class Program
{
    static void Main(string[] args)
    {

        string en = Console.ReadLine();
        double r = double.Parse(en);
        
        Console.WriteLine((r * r * Math.PI).ToString("f6") + " " + ((r + r) * Math.PI).ToString("f6"));

        //Console.Read();
    }
}
//}