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 (Clang 10.0.0) (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

int compare_llint_rise(const void *a, const void *b) {
	long long int A, B;
	A = *(long long int *)a;
	B = *(long long int *)b;
	if(A < B) {
		return -1;
	} else if (A > B){
		return 1;
	} else {
		return 0;
	}
}

int main(void) {
	int N;
	long long int *A;
	int i;
	int count;
	char buf[128], *ch;

	fgets(buf, sizeof(buf), stdin);
	ch = strtok(buf, " ");
	N = atoi(ch);
	A = (long long int *)calloc(N, sizeof(long long int));
	for(i = 0; i < N; i += 1) {
		fgets(buf, sizeof(buf), stdin);
		ch = strtok(buf, " ");
		A[i] = atoll(ch);
	}

	qsort(A, N, sizeof(long long int), compare_llint_rise);

	count = 1;
	for(i = 1; i < N; i += 1) {
		if(A[i] == A[i - 1]) {
			count -= 1;
			A[i] = -1;
		} else {
			count += 1;
		}
	}

	printf("%d\n", count);

	free(A);
	return 0;
}