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: Time Limit Exceeded)

#include <stdio.h>

void swap(int*, int*);

void sort(int *a, int N) {
  int i, j, min, k = 0;

  for (k = 0; k < N; k++) {
    min = *(a + k);
    j = k;
    for (i = k + 1; i < N; i++) {
      if (min > *(a + i)) {
        min = *(a + i);
        j = i;
      }
    }
    swap(a + k, a + j);
  }
}

void swap (int *a, int *b) {
  int k;
  k = *a;
  *a = *b;
  *b = k;
}

int main() {
  int N, i, j, num = 0, n = 0;
  int a[100000];

  scanf("%d", &N);

  for (i = 0; i < N; i++) {
    scanf("%d", &a[i]);
  }
  sort(&a[0], N);
  i = 0;
  while (i < N) {
    j = a[i];
    while (i < N && j == a[i]) {
      i++;
      n++;
    }
    n %= 2;
    num += n;
    n = 0;
  }
  printf("%d\n", num);

  return 0;
}