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 <stdlib.h>

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

int main(void){
  long N;
  long ans = 0;
  scanf("%ld",&N);

  long long A[N];
  for(int i = 0;i < N;i++) scanf("%lld",&A[i]);

  qsort(A,N,sizeof(long),compare_int);

  for(int i = 0;i < N;i++){
    int sample = A[i];
    int counter = 0;
    while(1){
      if(i+counter >= N) break;
      if(A[i+counter] != sample) break;
      counter++;
    }
    if(counter%2 != 0) ans++;
    i += counter-1;
  }

  printf("%ld",ans);
  return 0;
}