output_description: If it is possible to give cookies so that each of the three goats can have the
  same number of cookies, print `Possible`; otherwise, print `Impossible`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B
attempt: A, B = map(int, input().split())
          print("No")
  
  if A % 3 == 0 or B % 3 == 0 or (A + B) % 3 == 0:
      print("Possible")
  else:
      print("Impossible")
  
problem_description: Statement
  
  Snuke is giving cookies to his three goats.
  
  He has two cookie tins. One contains A cookies, and the other contains B
  cookies. He can thus give A cookies, B cookies or A+B cookies to his goats (he
  cannot open the tins).
  
  Your task is to determine whether Snuke can give cookies to his three goats so
  that each of them can have the same number of cookies.
samples: [{"input": "4 5", "output": "Possible\n    \n\nIf Snuke gives nine cookies, each of the three goats can have three cookies.\n\n* * *"}, {"input": "1 1", "output": "Impossible\n    \n\nSince there are only two cookies, the three goats cannot have the same number\nof cookies no matter what Snuke gives to them."}]