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: Accepted)

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <map>
#include <set>
#include <queue>
#include <time.h>
#pragma comment (linker, "/STACK:200000000")
#define ll long long
#define mod 1000000007ll
#define maxn 1000000ll
using namespace std;


//fstream cin("input.txt"); ofstream cout("output.txt");
//fstream cin("hobby.in"); ofstream cout("hobby.out");
ll gcd(ll a, ll b) {
	while (b) {
		a %= b;
		swap(a, b);
	}
	return a;
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	int n;
	cin >> n;
	map<int, bool> m;
	for (int i = 0; i < n; i++) {
		int a;
		cin >> a;
		if (m[a] == 0) m[a] = 1;
		else m[a] = 0;
	}
	int k = 0;
	for (auto i : m) {
		if (i.second == 1) {
			k++;
		}
	}
	cout << k;
	return 0;
}