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 aizu{
    public static int Main(){
        int i;
        double[] n = new double[100];
        string[] str = new string[100];
        str = Console.ReadLine().Split(' ');
        for(i=0;i<1;i++)
            n[i] = double.Parse(str[i]);
        Console.WriteLine("{0:f8} {1:f8}",n[0]*n[0]*Math.PI,2*n[0]*Math.PI);
        return 0;
    }
}