output_description: Print the maximum number of happiness points that can be earned.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      X
attempt: x = int(input("x: "))
  tot = int(x / 500)
  y = x - tot * 500
  tot = tot * 1000 + int(y / 5) * 5
  print(tot)
  
problem_description: Statement
  
  Takahashi loves gold coins. He gains 1000 _happiness points_ for each 500-yen
  coin he has and gains 5 happiness points for each 5-yen coin he has. (Yen is
  the currency of Japan.)
  
  Takahashi has X yen. If he exchanges his money so that he will gain the most
  happiness points, how many happiness points will he earn?
  
  (We assume that there are six kinds of coins available: 500-yen, 100-yen,
  50-yen, 10-yen, 5-yen, and 1-yen coins.)
samples: [{"input": "1024", "output": "2020\n    \n\nBy exchanging his money so that he gets two 500-yen coins and four 5-yen\ncoins, he gains 2020 happiness points, which is the maximum number of\nhappiness points that can be earned.\n\n* * *"}, {"input": "0", "output": "0\n    \n\nHe is penniless - or yenless.\n\n* * *"}, {"input": "1000000000", "output": "2000000000\n    \n\nHe is a billionaire - in yen."}]