output_description: Print the answer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      H
      W
attempt: a = [int(input()) for _ in range(3)]
  print((a[0] + 1 - a[1]) * (a[0] + 1 - a[2]))
  
problem_description: Statement
  
  It has been decided that a programming contest sponsored by company A will be
  held, so we will post the notice on a bulletin board.
  
  The bulletin board is in the form of a grid with N rows and N columns, and the
  notice will occupy a rectangular region with H rows and W columns.
  
  How many ways are there to choose where to put the notice so that it
  completely covers exactly HW squares?
samples: [{"input": "3\n    2\n    3", "output": "2\n    \n\nThere are two ways to put the notice, as follows:\n\n    \n    \n    ###   ...\n    ###   ###\n    ...   ###\n    \n\nHere, `#` represents a square covered by the notice, and `.` represents a\nsquare not covered.\n\n* * *"}, {"input": "100\n    1\n    1", "output": "10000\n    \n\n* * *"}, {"input": "5\n    4\n    2", "output": "8"}]