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++ (GCC 9.2.1) (judge verdict: Time Limit Exceeded)

#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
#define PI 3.1415926535897932
#define MOD 1000000007;
using namespace std;
long long GCD(long long A,long long B){
  if(B==0){
    return A;
  }
  else{
    return GCD(B,A%B);
  }
}
long long LCM(long long A,long long B){
  long long g=GCD(A,B);
  return A/g*B;
}
long long num_order(long long X){
  long long ans=0;
  while(true){
    if(X==0){
      break;
    }
    else{
      X/=10;
      ans++;
    }
  }
  return ans;
}
int main() {
  
  int N;
  cin>>N;
  
  vector<int> A(N);
  for(int i=0;i<N;i++){
    cin>>A[i];
  }
  
  set<int> S;
  for(int i=0;i<N;i++){
    S.insert(A[i]);
  }
  
  int ans=0;
  
  
  while(!(S.empty())){
    int sum=count(A.begin(),A.end(),*begin(S));
    
    if(sum%2==1){
      ans++;
    }
    
    S.erase(*begin(S));
  }
  
  cout<<ans<<endl;
}