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 9.2.1) (judge verdict: Accepted)

/**
*    created: 04.07.2020 20:51:00
**/
#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
// #include <boost/multiprecision/cpp_int.hpp>
// using bint = boost::multiprecision::cpp_int;
using namespace std;
#define int long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define pcnt(bit) __builtin_popcountll(bit)
template<class T> bool chmax(T &a, const T &b) {if (a < b) {a = b; return 1;} return 0;}
template<class T> bool chmin(T &a, const T &b) {if (b < a) {a = b; return 1;} return 0;}
const long double pi = acos(-1.0);
const int INF = 1LL << 60;
const int MOD = 1000000007;
// const int MOD = 998244353;

signed main() {

    cin.tie(0);
    ios_base::sync_with_stdio(false);

    int n;
    cin >> n;
    map<int,int> mp;
    rep(i,n) {
        int a;
        cin >> a;
        if (mp[a] == 0) mp[a]++;
        else mp.erase(a);
    }
    cout << mp.size() << endl;
    return 0;
}