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 <iostream>
#include <cstdio>
#include <vector>
#include <cstring>
#include <bitset>
#include <cmath>
#include <iomanip>
#include <stack>
#include <set>
#include <queue>
#include <algorithm>
#include <deque>
#include <map>
#include <cmath>
#include <iomanip>
using namespace std;

#define INF 1e18
#define int long long

signed main() {
    int n; cin >> n;
    map<int, int> mp;
    for(int i = 0; i < n; i++) {
        int a; cin >> a;
        if(mp[a] > 0) mp[a]--;
        else mp[a]++;
    }

    int ans = 0;
    for(auto i = mp.begin(); i != mp.end(); i++) {
        ans += i -> second;
    }

    cout << ans << endl;
    return 0;
}