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 JavaScript (node.js v5.12) (judge verdict: Accepted)

function Main(s) {
  var s = s.split("\n").map(e => e*1);
  var b = new Map();
  var cnt = 0;
  for (var i = 1; i <= s[0]; i++) {
    if (!b.has(s[i])) {
      b.set(s[i], 1);
    } else {
      b.set(s[i], b.get(s[i]) + 1);
    }
  }
  cnt = 0;
  for (var i of b.values()) {
    if (i&1) cnt++;
  }
  console.log(cnt);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));