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: # https://atcoder.jp/contests/abc073/tasks/abc073_c
  # 偶数個を抜くだけ
  import sys
  
  sys.setrecursionlimit(1 << 25)
  read = sys.stdin.readline
  ra = range
  enu = enumerate
  
  
  def exit(*argv, **kwarg):
      print(*argv, **kwarg)
      sys.exit()
  
  
  def mina(*argv, sub=1):
      return list(map(lambda x: x - sub, argv))
  
  
  # 受け渡されたすべての要素からsubだけ引く.リストを*をつけて展開しておくこと
  
  
  def a_int():
      return int(read())
  
  
  def read_col(H):
      """H is number of rows
      A列、B列が与えられるようなとき
      ex1)A,B=read_col(H)    ex2) A,=read_col(H) #一列の場合"""
      ret = []
      for _ in range(H):
          ret.append(list(map(int, read().split())))
      return tuple(map(list, zip(*ret)))
  
  
  from collections import Counter
  
  N = a_int()
  (A,) = read_col(N)
  ans = 0
  for v in Counter(A).values():
      ans += v & 1
  print(ans)
  
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"}]