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: import sys
  from functools import lru_cache, cmp_to_key
  from heapq import merge, heapify, heappop, heappush
  from math import *
  from collections import defaultdict as dd, deque, Counter as C
  from itertools import combinations as comb, permutations as perm
  from bisect import bisect_left as bl, bisect_right as br, bisect
  from time import perf_counter
  from fractions import Fraction
  
  # sys.setrecursionlimit(int(pow(10, 2)))
  # sys.stdin = open("input.txt", "r")
  # sys.stdout = open("output.txt", "w")
  mod = int(pow(10, 9) + 7)
  mod2 = 998244353
  
  
  def data():
      return sys.stdin.readline().strip()
  
  
  def out(*var, end="\n"):
      sys.stdout.write(" ".join(map(str, var)) + end)
  
  
  def l():
      return list(sp())
  
  
  def sl():
      return list(ssp())
  
  
  def sp():
      return map(int, data().split())
  
  
  def ssp():
      return map(str, data().split())
  
  
  def l1d(n, val=0):
      return [val for i in range(n)]
  
  
  def l2d(n, m, val=0):
      return [l1d(n, val) for j in range(m)]
  
  
  # @lru_cache(None)
  N = l()[0]
  s = set()
  for i in range(N):
      a = l()[0]
      if a in s:
          s.discard(a)
      else:
          s.add(a)
  print(len(s))
  
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"}]