output_description: Print how many numbers will be written on the sheet at the end of the game.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1
      :
      A_N
attempt: def ai():
      return input()  # s
  
  
  def a():
      return int(input())  # a,n or k
  
  
  def ma():
      return map(int, input().split())  # a,b,c,d or n,k
  
  
  def ms():
      return map(str, input().split())  # ,a,b,c,d
  
  
  def lma():
      return list(map(int, input().split()))  # x or y
  
  
  def lms():
      return list(map(str, input().split()))  # x or y
  
  
  k = []
  l = []
  f = 0
  
  
  def say(i):
      return print("Yes" if i == 0 else "No")
  
  
  def Say(i):
      return print("YES" if i == 0 else "NO")
  
  
  a = int(input())
  c = set()
  for i in range(a):
      t = int(input())
      if t in c:
          c.remove(t)
      else:
          c.add(t)
  print(len(c))
  
problem_description: Statement
  
  You are playing the following game with Joisino.
  
    * Initially, you have a blank sheet of paper.
    * Joisino announces a number. If that number is written on the sheet, erase the number from the sheet; if not, write the number on the sheet. This process is repeated N times.
    * Then, you are asked a question: How many numbers are written on the sheet now?
  
  The numbers announced by Joisino are given as A_1, ... ,A_N in the order she
  announces them. How many numbers will be written on the sheet at the end of
  the game?
samples: [{"input": "3\n    6\n    2\n    6", "output": "1\n    \n\nThe game proceeds as follows:\n\n  * 6 is not written on the sheet, so write 6.\n\n  * 2 is not written on the sheet, so write 2.\n\n  * 6 is written on the sheet, so erase 6.\n\nThus, the sheet contains only 2 in the end. The answer is 1.\n\n* * *"}, {"input": "4\n    2\n    5\n    5\n    2", "output": "0\n    \n\nIt is possible that no number is written on the sheet in the end.\n\n* * *"}, {"input": "6\n    12\n    22\n    16\n    22\n    18\n    12", "output": "2"}]