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)

#include<iostream>
#include<string.h>
#include<algorithm>
using namespace std;
#include<set>
#pragma warning(disable:4996)
set<int> s;
void zaichangnei() {
	freopen("inputfile2.txt", "r", stdin);
	int N = 0;
	while (scanf("%d", &N) != EOF) {
		s.clear();
		for (int i = 0; i < N; i++) {
			int tmp = 0;
			scanf("%d", &tmp);
			if (s.find(tmp) == s.end())s.insert(tmp);
			else s.erase(tmp);
		}
		printf("%d\n", s.size());
	}
}
int main() {
	//baixianguo();
	//diancai();
	zaichangnei();
	return 0;
}