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;
class Aoj
{
    public static void Main()
    {
        String[] st = Console.ReadLine().Split(' ');
        double a = double.Parse(st[0]);
        double r = a * a *Math.PI;
        double f = a * 2 * Math.PI;
        Console.WriteLine("{0} {1}",r,f);
    }

}