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: import sys
  from io import StringIO
  import unittest
  
  
  def resolve():
      n = int(input())
      s = [input() for _ in range(n)]
  
      print(len(set(s)))
  
  
  class TestClass(unittest.TestCase):
      def assertIO(self, input, output):
          stdout, stdin = sys.stdout, sys.stdin
          sys.stdout, sys.stdin = StringIO(), StringIO(input)
          resolve()
          sys.stdout.seek(0)
          out = sys.stdout.read()[:-1]
          sys.stdout, sys.stdin = stdout, stdin
          self.assertEqual(out, output)
  
      def test_入力例_1(self):
          input = """3
  apple
  orange
  apple"""
          output = """2"""
          self.assertIO(input, output)
  
      def test_入力例_2(self):
          input = """5
  grape
  grape
  grape
  grape
  grape"""
          output = """1"""
          self.assertIO(input, output)
  
      def test_入力例_3(self):
          input = """4
  aaaa
  a
  aaa
  aa"""
          output = """4"""
          self.assertIO(input, output)
  
  
  if __name__ == "__main__":
      # unittest.main()
      resolve()
  
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"}]