output_description: Print an integer representing the area of the regular dodecagon.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      r
attempt: A = input()
  print(3 * A**2)
  
problem_description: Statement
  
  It is known that the area of a regular dodecagon inscribed in a circle of
  radius a is 3a^2.
  
  Given an integer r, find the area of a regular dodecagon inscribed in a circle
  of radius r.
samples: [{"input": "4", "output": "48\n    \n\nThe area of the regular dodecagon is 3 \\times 4^2 = 48.\n\n* * *"}, {"input": "15", "output": "675\n    \n\n* * *"}, {"input": "80", "output": "19200"}]