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: Time Limit Exceeded)

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <vector>
#include <queue>
#include <ctime>
#include <map>
#include <iomanip>
using namespace std;
 
#define FOR(i,a,b) for (ll i = (a); i < (b); i++)
#define REP(i,n) FOR(i,0,n)
 
long gcd(long long a, long long b){
	if (a%b==0){
		return b;
	}
	else{
		return gcd(b,a%b);
	}
}
 
long lcm(long long a, long long b){
	return a / gcd(a,b) * b;
}
 
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a < b) { a = b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a > b) { a = b; return 1; } return 0; }
 
typedef long long ll;
 
const ll INF = 1ll<<60;
const ll MOD = 1000000007;
const double EPS = 1e-10;

int n;
ll a[112345];
ll cnt;

int main(){
	cin >> n;
	
	REP(i,n){
		cin >> a[i];
		
		REP(j,i){
			if (a[i] != a[j]) continue;
			
			a[i] = 0;
			a[j] = 0;
			
			cnt++;
			break;
		}
	}
	
	cout << n-(2*cnt) << endl;
	
	return 0;
}