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++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, n) for(int i=0;i<(int)n;i++)
#define PI acos(-1)
#define fast_io ios_base::sync_with_stdio(false) ; cin.tie(0); cout.tie(0);
ll mod=1e9+7;
bool flag[100100100]={};
int main(){
    fast_io
    
    ll n;
    cin>>n;
    ll a[n];
    rep(i,n) cin>>a[i];

    ll ans=0;
    rep(i,n){
        if(flag[a[i]]==0){
            flag[a[i]]=1;
            ans++;
        }else{
            flag[a[i]]=0;
            ans--;
        }
    }
    cout<<ans<<endl;
    return 0;
}