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>
#include <algorithm>

#define rep1(i, a, n) for (int i = a; i < n; i++)
#define rep2(i, a, n) for (int i = n; i >= a; i--)
#define asc(v) sort(v.begin(), v.end())
#define desc(v) sort(v.begin(), v.end(), greater<int>())

using namespace std;

int main() {
  int N, ptr = 0, ans = 0;
  cin >> N;
  vector<int> A(N, 0);
  rep1(i, 0, N) cin >> A[i];
  asc(A);
  while (ptr < N) {
    int cur = A[ptr], cnt = 0;
    while (ptr < N && cur == A[ptr]) {
      cnt++;
      ptr++;
    }
    ans += cnt % 2;
  }
  cout << ans << endl;
  return 0;
}