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 (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include <stdio.h>

int main() {
	int n, j, a[100010] = {};
	int z, ans = 0;
	long int k;

	scanf("%d", &n);

	for (int i = 0; i < n; i++)
	{
		z = 0;
		scanf("%d", &k);
		for (j = 0; j < i; j++)
		{
			if (a[j] == k)
			{
				a[j] = 0;
				ans--;
				break;
			}
			else if (a[j] == 0)
			{
				z = j;
			}
		}
		if (j == i)
		{
			a[(z > 0) ? z : j] = k;
			ans++;
		}
	}

	printf("%d", ans);
	return 0;
}