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: Accepted)

#include<stdio.h>
#include<stdlib.h>
int compar(const int *val1, const int *val2);
int main(){
    	int N,A[100000],i,j,res=0,flag=1;
    	scanf("%d",&N);
    	for(i=0;i<N;i++){
    		scanf("%d",&A[i]);
    	}
    	qsort(A,N,sizeof(int),(int (*)(const void *, const void *))compar);
    	/*for(i=0;i<N;i++){
			for(j=N-1;j>i;j--){
				if(A[j]>A[j-1]){
					A[j]^=A[j-1];
					A[j-1]^=A[j];
					A[j]^=A[j-1];
				}
			}
    	}*/
    	/*for(i=0;i<N;i++){
    		printf("配列＝%d\n",A[i]);
    	}*/
    	for(i=0;i<N;i++){
    		if(A[i]==A[i+1]){
    			flag++;
    			//printf("aa=%d",flag);
    		}else{
    			//printf("flag=%d\n",flag);
    			res+=flag%2;
    			flag=1;
    		}
    	}
    	printf("%d\n",res);
    	return 0;
    }
int compar(const int *val1, const int *val2) {
    if ( *val1 < *val2 ) {
        return -1;
    } else if ( *val1 == * val2 ) {
        return 0;
    } else {
        return 1;
    }
}