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 <string.h>

int ascSort(const void* v1, const void* v2) {
    const int _v1 = *((const int*)v1);
    const int _v2 = *((const int*)v2);
 
    if ( _v1 > _v2 ) {
        return 1;
    } else if ( _v1 < _v2 ) {
        return -1;
    } else {
        return 0;
    }
}

int main(){
  int n,i,ans,count=0,look=0;
  scanf("%d",&n);
  int a[1000000],b[100000];
  for(i=0;i<1000000;i++){
    a[i]= -1;
    b[i]= 0;
  }
  for(i=0;i<n;i++){
    scanf("%d",&a[i]);
  }
  qsort(a,n,sizeof(a[0]),ascSort);
  for(i=0;i<n;i++){
    if(a[i]==a[i+1]){
      count += 1;
    }else{
      b[look] = count + 1;
      look += 1;
      count = 0;
    }
  }
  for(i=0;i<look;i++){
    ans += b[i]%2;
  }
  printf("%d",ans);
  return 0;
}