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# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System.Collections.Generic;
using System.Linq;
using System;
class Program
{
    static void Main()
    {
        int count = int.Parse(Console.ReadLine());
        int[] array = new int[count];
        for (int i = 0; i < count; i++)
        {
            array[i] = int.Parse(Console.ReadLine());
        }
        Array.Sort(array);


        int before = -1;
        int result = 0;
        int streak = 0;
        for (int i = 0; i < count; i++){
            if (array[i] == before){
                streak++;

                if(i == count - 1){
                    if (streak % 2 != 0)
                        result++;
                }
                
            }else{
                if (streak % 2 != 0)
                    result++;
                
                streak = 1;
                before = array[i];
            }
        }

        Console.WriteLine(result);
    }
}