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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

//abc073_c.cpp
//Sat May 26 14:04:31 2018

#include <iostream>
#include <string>
#include <queue>
#include <unordered_map>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
	int n;
	cin >> n;

	int a[n];
	for (int i=0;i<n;i++){
		cin >> a[i];
	}

	sort (a,a+n);

	int prevnum = -1;
	int count = 0;
	int ansnum = 0;

	for (int i=0;i<n;i++){
		if (a[i] != prevnum){
			if (prevnum != -1 && count%2==1){
				ansnum++;
			}
			prevnum = a[i];
			count = 1;
		}else{
			count++;
		}
	}

	cout << ansnum << endl;
}