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 PHP7 (7.0.15) (judge verdict: Accepted)

<?php
fscanf(STDIN,"%d",$n);
$a_count = array();
for($i=0;$i<$n;$i++){
  fscanf(STDIN,"%d",$a);
  if($a_count[$a] == 0 || !isset($a_count[$a])){
      $a_count[$a]++;
  }else{
      $a_count[$a] = 0;
  }

}

sort($a_count);
$count = 0;
foreach($a_count as $a){
  if($a == 1){
      $count++;
  }
}

echo $count."\n";