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: Accepted)

#include <stdio.h>
#include <stdlib.h>
#define REP(i, n) for(i = 0; i < n; ++i)
#define FOR(i, a, b) for(i = a; i < b; ++i)

void yes_or_no(char boolean){
    if(boolean){
        printf("Yes\n");
    }else{
        printf("No\n");
    }
}

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

int main(){
    int N, i;
    scanf("%d", &N);
    long list[N];

    REP(i, N){
        scanf("%ld", &list[i]);
    }
    qsort(list, N, sizeof(long), comp);

    int num = 1;
    int ans = 0;

    if(N == 1){
        ans = 1;
    }

    FOR(i, 1, N){
        if(list[i - 1] == list[i]){
            num++;
        }else{
            ans += (num % 2);
            num = 1;
        }
    }
    
    ans += (num % 2);

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