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: import glob
  
  
  # 問題ごとのディレクトリのトップからの相対パス
  REL_PATH = "ABC\\134\\A"
  
  # テスト用ファイル置き場のトップ
  TOP_PATH = "C:\\AtCoder"
  
  
  class Common:
      problem = []
      index = 0
  
      def __init__(self, rel_path):
          self.rel_path = rel_path
  
      def initialize(self, path):
          file = open(path)
          self.problem = file.readlines()
          self.index = 0
          return
  
      def input_data(self):
          try:
              IS_TEST
              self.index += 1
              return self.problem[self.index - 1]
  
          except NameError:
              return input()
  
      def resolve(self):
          pass
  
      def exec_resolve(self):
          try:
              IS_TEST
              for path in glob.glob(TOP_PATH + "\\" + self.rel_path + "/*.txt"):
                  print("Test: " + path)
                  self.initialize(path)
                  self.resolve()
                  print("\n\n")
          except NameError:
              self.resolve()
  
  
  class A(Common):
  
      def resolve(self):
  
          r = int(self.input_data())
          print(str(3 * r * r))
  
  
  solver = A(REL_PATH)
  solver.exec_resolve()
  
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"}]