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>
int main(void){
    int num_try;
    int *paper;
    int  load;
    int flag=0;
    int count=0;

    scanf("%d",&num_try);
    paper=(int *)malloc(sizeof(int)*num_try);
    int i,j;

    for(i=0;i<num_try;i++){
        paper[i]=0;
    }


    for(i=0;i<num_try;i++){
        scanf("%d",&load);
        for(j=0;j<i;j++){
            if(paper[j]==load){
                paper[j]=0;
                count--;
                flag++;
            }
        }
        if(flag==0){
            paper[i]=load;
            count++;
        }
        flag=0;
    }

    /*for(i=0;i<num_try;i++){
        if(paper[i]!=0){
            count++;
        }
    }*/
    printf("%d",count);
    
    free(paper);

    return 0;
}