output_description: 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.
input_description: A real number r is given.
attempt: x = input()
  x = float(x)
  print("%f %f" % (x**2 * 3.1415926535, 2 * 3.1415926535 * x))
  
problem_description: Circle
  
  Write a program which calculates the area and circumference of a circle for
  given radius r.
samples: [{"input": "2", "output": "12.566371 12.566371"}, {"input": "3", "output": "28.274334 18.849556"}]