output_description: Print the maximum possible volume of a rectangular cuboid whose sum of the
  dimensions (not necessarily integers) is L. Your output is considered correct
  if its absolute or relative error from our answer is at most 10^{-6}.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      L
attempt: print(((input()) / 3) ** 3)
  
problem_description: Statement
  
  Given is a positive integer L. Find the maximum possible volume of a
  rectangular cuboid whose sum of the dimensions (not necessarily integers) is
  L.
samples: [{"input": "3", "output": "1.000000000000\n    \n\nFor example, a rectangular cuboid whose dimensions are 0.8, 1, and 1.2 has a\nvolume of 0.96.\n\nOn the other hand, if the dimensions are 1, 1, and 1, the volume of the\nrectangular cuboid is 1, which is greater.\n\n* * *"}, {"input": "999", "output": "36926037.000000000000"}]