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: Wrong Answer)

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

int asc(const void *a, const void *b) {
  return *(int *)a - *(int *)b;
}

int main()
{
    int n,a[100001],i,left = 0,ans = 0;

    scanf("%d",&n);
    for (i = 0; i < n; i++)
    {
        scanf("%d",&a[i]);
    }
    a[i] = 1000000001;

    qsort(a,n,sizeof(int),asc);

    if(n != 1)
    {
        for (i = 1; i < n; i++)
        {
            if(a[i] != a[i - 1])
            {
                ans += (i - left) % 2;
                left = i;
            }
        }
        printf("%d\n",ans);
    }
    else
    {
        printf("1\n");
    }
}