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>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <math.h>

/*ソートの時に使う
int sort(const void *a, const void *b){
    return *(int*)a-*(int*)b ;
}
    qsort (data,sizeof(data),sizeof(int),sort); 
*/

int main(void){
    int n;
    scanf("%d",&n);
    int a[n];
    bool s[n];
    for (int i=0; i<n; i++){
        scanf("%d",&a[i]);
        s[i]=true;
    }
    for (int i=0; i<n; i++){
        for (int j=i+1; j<n; j++){
            if (s[i]==true && s[j]==true && a[i]==a[j]){
                s[i]=false;
                s[j]=false;
                break;
            }
        }
    }
    int ans=0;
    for (int i=0; i<n; i++){
        if (s[i]==true){
            ans++;
        }
    }
    
    printf("%d\n",ans);
	return 0 ;
}