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<string.h>
#include<stdlib.h>
int count=0;
typedef struct node{
  int x;
  struct node *next;
}node;
void add(int x,node *nodex){
  if(nodex->next==NULL){
    node *new=malloc(sizeof(node));
    new->next=nodex->next;
    new->x=x;
    nodex->next=new;
    return;
  }else if(x<nodex->next->x){
    node *new=malloc(sizeof(node));
    new->next=nodex->next;
    new->x=x;
    nodex->next=new;
    return;
  }else if(x>nodex->next->x){
    add(x,nodex->next);
    return;
  }else if(x==nodex->next->x){
    node *temp=nodex->next;
    nodex->next=nodex->next->next;
    free(temp);
    return;
  }
}
int main(){
  int i,n,x;
  node root;
  root.next=NULL;
  root.x=0;
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&x);
    add(x,&root);
  }
  node *temp=&root;
  while(temp->next!=NULL){
    count++;
    temp=temp->next;
  }
  printf("%d\n",count );
}