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 <string>
#include <sstream>
#include <cmath>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include <numeric>
using namespace std;
typedef long long LL;
LL i,j,k,n,m;
LL mod=1000000007;
string s;

int main() {
  cin >>n;
  map<LL, LL> mp;
  for(i=0;i<n;++i) {
    LL t;cin >> t;
    if(mp.find(t) != mp.end()) {
      mp.at(t) = mp.at(t) + 1;
    } else {
      mp.insert(make_pair(t,1));
    }
  }
  int cnt=0;
  for(auto itr=mp.begin();itr !=mp.end();++itr){
    if((*itr).second%2 != 0) ++cnt;
  }
  cout << cnt << endl;
  return 0;
}