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: Accepted)

#include <bits/stdc++.h>
#include <stdio.h>
#include <cmath>

using namespace std;

#define rep(i,n) for(long long i=0; i<(long long)(n);i++)
//rep…「0からn-1まで」の繰り返し
#define rep2(i,s,n) for(long long i=s; i<=(long long)(n);i++)
//rep2…「sからnまで」の繰り返し
#define repr(i,s,n) for(long long i=s;i>=(long long)(n);i--)
//repr…「ｓからnまで」の降順の繰り返し

typedef long long ll;

const ll inf = 1e18+7;
const ll mod = 1e9+7;

//階乗
int factorial(int k){
    int result=1;
    for (int i=1;i<=k;++i){
        result*=i;
    }
    return result;
}

int main() {
    ll n;
    cin>>n;

    map<ll,ll>a;
    rep(i,n){
        ll x;
        cin>>x;

        a[x]++;
    }

    ll ans=0;

    for (auto i : a) {
        if(i.second%2!=0)ans++;
    }

    cout<<ans<<endl;
}