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: Accepted)

#include <stdio.h>


long long temp[100000];

void MergeSort(long long x[], long long left, long long right);


void MergeSort(long long x[], long long left, long long right)
{
	long long mid, i, j, k;

	if (left >= right)              
		return;                    

									
	mid = (left + right) / 2;      
	MergeSort(x, left, mid);        
	MergeSort(x, mid + 1, right);  

									
	for (i = left; i <= mid; i++)
		temp[i] = x[i];

	
	for (i = mid + 1, j = right; i <= right; i++, j--)
		temp[i] = x[j];

	i = left;        
	j = right;       

	for (k = left; k <= right; k++)   
		if (temp[i] <= temp[j])      
			x[k] = temp[i++];
		else
			x[k] = temp[j--];
}

int main()
{
	long long n, i, b, k;
	long long a[100000];
	long long c = 0;
	scanf("%lld", &n);
	for (i = 0; i < n; i++) {
		scanf("%lld", &a[i]);
	}

	MergeSort(a, 0, n - 1);

	for (i = 0; i < n; i++) {
		if (a[i] == a[i + 1]) {
			c+=2;
			i++;
		}
	}
	printf("%lld", n - c);
	return 0;
}