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>
#include<stdlib.h>
#include<math.h>
#include<string.h>
typedef long long int ll;
void swap(ll *x,ll *y){ll temp;temp=*x;*x=*y;*y=temp;}
int compare_asc(const void *a,const void *b){return *(int*)a-*(int*)b;}
int compare_desc(const void *a,const void *b){return *(int*)b-*(int*)a;}

int main(){
    static ll n,a[200000],ans=0,max=-1;
    int i,j,k;

    scanf("%lld",&n);
    for(i=0;i<n;i++)scanf("%lld",&a[i]);

    //qsort(a,n,sizeof(ll),compare_asc);
    for(i=0;i<n-1;i++){
        for(j=i+1;j<n;j++){
            if(a[i]>a[j])swap(&a[i],&a[j]);
        }
    }
    int cnt;
    ll tmp=a[0];
    cnt=1;

    for(i=1;i<n;i++){
        if(a[i]!=tmp){
            tmp=a[i];
            if(cnt%2)ans++;
            cnt=1;
        }else{
            cnt++;
        }
    }
    if(cnt%2)ans++;
    printf("%lld\n",ans);
    return 0;
}