Problem:
Score : 300 points

Problem 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?

Constraints

1≤N≤100000

1≤A_i≤1000000000(=10^9)

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
A_1
:
A_N

Output

Print how many numbers will be written on the sheet at the end of the game.

Sample Input 1

3
6
2
6

Sample Output 1

1

The game proceeds as follows:

6 is not written on the sheet, so write 6.

2 is not written on the sheet, so write 2.

6 is written on the sheet, so erase 6.

Thus, the sheet contains only 2 in the end. The answer is 1.

Sample Input 2

4
2
5
5
2

Sample Output 2

0

It is possible that no number is written on the sheet in the end.

Sample Input 3

6
12
22
16
22
18
12

Sample Output 3

2

Solution in PHP (7.4.4) (judge verdict: Accepted)

<?php
  list($n) = explode(" ", trim(fgets(STDIN)));

  $ans = [];
  for ($i=0; $i<$n; $i++) {
    list($a) = explode(" ", trim(fgets(STDIN)));
    if(!isset($ans[$a])) {
      $ans[$a] = true;
    }else {
      if($ans[$a]) $ans[$a] = false;
      else $ans[$a] = true;
    }
  }

  $x = 0;
  foreach ($ans as $k => $v) {
    if($v) $x++;
  }

  echo $x;