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 9.2.1) (judge verdict: Accepted)

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

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

int main(void){
     long int n,i,c=0,k=0,j,m[100100]={0};
    long long int a[100090];

   scanf("%ld",&n);

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

    qsort(a, n, sizeof(long long int), cmpfunc);

    a[n]=-5;

    for(i=0;i<n;i++){
        if(a[i]==a[i+1]){
            m[k]++;
        }
        else{
            k++;
        }
    }

    for(i=0;i<k;i++){
        if(m[i]%2==0){c++;}
        else if(k==n){c=k;break;}
    }

    printf("%ld",c);

    return 0;
}