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;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program2
    {
        static void Main()
        {

            List<long> num = new List<long>();
            long a, c;
            int d = 0;

            c = int.Parse(Console.ReadLine());


            for (int i = 0; i < c; i++)
            {
                string[] str = Console.ReadLine().Split(' ');//2つ以上のスペース区切り入力の取得
                a = int.Parse(str[0]);  //数値で受け取りたい場合は変換する
                if (i == 0)
                {
                    num.Add(a);
                    d++;
                }
                for (int j = 0; j < d; j++)
                {
                    if (num[j] == a)
                    {
                        num.RemoveAt(j);
                        d--;
                        goto END;
                    }
                }

                num.Add(a);
                d++;
                END:;
            }
            if(d > 0)
            d--;
            Console.Write(d);
        }
    }
}