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: Time Limit Exceeded)

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

namespace ConsoleApplication
{
    class Program
    {
        static void Main()
        {
            new Solution().answer();
        }
    }

    class Solution
    {
        string N,M;
        string[] M_split = new string[2];
        int N1;
        int T = 0;
       
        public Solution()
        {
            N = Console.ReadLine().ToString();
            N1 = Convert.ToInt32(N);
            string[] A = new string[N1];
            int i;


            for (i = 1; i <= N1; i++)
            {
                M = Console.ReadLine();
                A[i - 1] = M;    
            }

            List<string> result = new List<string>();

            Array.ForEach(A, item => result.Add(item+","+ A.Where(p => item == p).Count()));
            result = result.Distinct().ToList();

            int k = result.Count;
            int r = 0;
            int a = 0;

            for (i = 0; i <= k - 1; i++)
            {
                r = result[i].IndexOf(",");
                a = result[i].ToString().Length-r-1;
                result[i] = result[i].Substring(r + 1, a);
            }


            for (i = 0; i <= k - 1; i++)
            {

                if (Convert.ToInt32(result[i]) % 2 != 0)
                {                    
                    T = T + 1;
                }
            }
        }

        public void answer()
        {

            Console.WriteLine(T.ToString());
        }
    }
}