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>
#include <stdlib.h>

int _compare(const void *a, const void *b) {
	if(*(int *)a < *(int *)b)
		return -1;
	else if(*(int *)a == *(int *)b)
		return 0;
	else
		return 1;
}

int main(void) {
	int N, ans, i, j, tar;
	long long int *A;

	scanf("%d", &N);
	getchar();
	A = (long long int *) malloc(sizeof *A * N);
	for(i = 0; i < N; i++) {
		scanf("%lld", &A[i]);
		getchar();
	}

	qsort(A, N, sizeof *A, _compare);
	i = j = tar = 0;
	while(j < N && i < N) {
		while(A[i] == A[j]) {
			j++;
			if(j == N)
				break;
		}
		if((j - i) % 2 == 1)
			tar++;
		i = j;
		j = i;
		if(i == N)
			break;
	}
	printf("%d", tar);

	free(A);

	return 0;
}