output_description: Print the number of kinds of items you got.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      S_1
      :
      S_N
attempt: row = int(input())
  item_list = [input() for i in range(row)]
  print(len(set(item_list)))
  
problem_description: Statement
  
  You drew lottery N times. In the i-th draw, you got an item of the kind
  represented by a string S_i.
  
  How many kinds of items did you get?
samples: [{"input": "3\n    apple\n    orange\n    apple", "output": "2\n    \n\nYou got two kinds of items: `apple` and `orange`.\n\n* * *"}, {"input": "5\n    grape\n    grape\n    grape\n    grape\n    grape", "output": "1\n    \n\n* * *"}, {"input": "4\n    aaaa\n    a\n    aaa\n    aa", "output": "4"}]