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 Ruby (judge verdict: Accepted)

# frozen_string_literal: true

r = gets.chomp.to_f
puts "#{format('%.10f', r * r * Math::PI)} #{format('%.10f', r * 2 * Math::PI)}"