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<math.h>
#include<list>
#include <algorithm>
#include<set>
#include<vector>
#include<math.h>
#include<map>
using namespace std;
using ll = long long;
using vll = vector<long long>;
using sll = set<long long>;

template<typename T>
T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }

#define in(x) cin >> x
#define out(x) cout << x
#define outn(x) cout << x << '\n'
#define outs(x) cout << x << ' '
#define rep(i,s,e) for(long i=s;i<e;i++)
#define repeq(i,s,e) for(long i=s;i<=e;i++)

int main() {
	ll n,a;
	in(n);

	sll sa;
	rep(i, 0, n) {
		in(a);
		if (sa.find(a)==sa.end()) {
			sa.insert(a);
		}
		else {
			sa.erase(a);
		}
	}

	outn(sa.size());
	
}