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: Runtime Error)

#include<stdio.h>

int main()
{
 int i;
  int s=0;
  int N;
  scanf("%d",&N);
  int *A;
  A = malloc(1000000000);
  if(A == 0) {
    fprintf(stderr, "メモリ確保エラー\n");
    return 0;
 }
  long a;
  for(i=0;i<N;i++){
    scanf("%ld",&a);
	if(A[a] == 0){
      s++;
      A[a]=1;
    }else{
      s--;
      A[a]=0;
    }
  }
  free(A);
  printf("%d",s);
  return 0;
}