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 (Clang 3.8.0) (judge verdict: Time Limit Exceeded)

#include <stdio.h>

int main(void)
{
    int n;
    scanf("%d", &n);
    long a;
    int i;
    long b[n];
    for (i = 0; i < n; i++)
        b[i] = 0;

    int j;
    int f = 0;

    for (i = 0; i < n; i++) {
        scanf("%ld", &a);
        f = 0;
        for (j = 0; j < i; j++) {
            if (b[j] == a) {
                b[j] = 0;
                f = 1;
                break;
            }
        }
        if (!f)
            b[j] = a;
    }
    int sum = 0;
    for (i = 0; i < n; i++) {
        if (b[i])
        sum++;
    }

    printf("%d\n", sum);
    return 0;
}