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>
#define ll long long
#define fi first
#define se second
#define show(x) cout<<#x<<"="<<x<<"\n"
using namespace std;

int n;
map<int,int> mp;

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
   cout.precision(10);
  cout<<fixed;
#ifdef LOCAL_DEFINE
    freopen("in", "r", stdin); 
    freopen("out","w",stdout);
#endif
    cin>>n;
    for(int i=0;i<n;i++){
    	int a;cin>>a;
    	if(mp[a]==0){
    		mp[a]=1;
    	}else mp[a]=0;
    }
    int ans=0;
    for(auto ite=mp.begin();ite!=mp.end();ite++){
    	if(ite->se==1)ans++;
    }
    cout<<ans<<"\n";
#ifdef LOCAL_DEFINE
    cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif
  return 0;
}