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: Memory Limit Exceeded)

#include <bits/stdc++.h>
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define SORTR(v,n) sort(v, v+n, greater<int>());
#define SORTPairSecond(v, n) sort(v, v+n, pairCompareSecond);
#define int long long    // %d=>%lld, 1<<n  => 1LL<<n
#define pb push_back

using namespace std;
typedef long long ll;

typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> piii;
typedef pair<ll, pll> plll;
bool pairCompareSecond(const pii& firstEl, const pii& secondEl) {
    return firstEl.second > secondEl.second;
}

const ll MOD = 1000000007;
const int INF = 1000000007;
// const int INF = 0x3f3f3f3f;
const ll LLINF = 0x3f3f3f3f3f3f3f3f;
// const ll LLINF = 1LL << 50;
const double PI = acos(-1);
const double EPS = 0.000000001;


const int MAX_n = 100000;
int n, a[MAX_n];

bool f[1000000000];

int ans;

signed main(){

    cin >> n;
    for(int i = 0;i < n;i++){
        cin >> a[i];
        if(f[a[i]] == 0){
            ans++;
            f[a[i]]=!f[a[i]];
        }else{
            ans--;
            f[a[i]]=!f[a[i]];
        }
    }
    cout<< ans<< endl;

    return 0;
}