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<bits/stdc++.h>
typedef long long ll;
#define REP(i,n) for(int i = 0;i < (n);i++)
#define rep(i,m,n) for(int i = (m);i < (n);i++)
#define P pair<int,int>
#define pb push_back
#define mk make_pair
using namespace std;
#define Vec(a) vector <int> a
const int INF = 1 << 20;
const int MOD = 1e9+7;





int main(){
  ll n;
  cin >> n;
  vector <ll> a;
  REP(i,n){
    ll b;
    cin >> b;
    a.pb(b);
  }
  sort(a.begin(),a.end());
  ll s = 1;
  ll ns = a[0];
  ll sum = 0;
  rep(i,1,n){
    if(a[i] == ns){
      s++;
    }
    else{
      ns = a[i];
      if(s%2 == 1)
	sum++;
      s = 1;
    }
  }
  if(s%2 == 1)
    sum++;
  cout << sum << endl;
  return 0;
}