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: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;
using System.IO;

namespace atcorder2
{
    class Program
    {
        public static long Read()
        {
            return long.Parse(Console.ReadLine());
        }

        public static long[] Reads()
        {

            return Console.ReadLine().Split().Select(long.Parse).ToArray();
        }


        public static long GCM(long x, long y)
        {
            var s = x;
            var t = y;
            if (x < y) GCM(y, x);
            while (y != 0)
            {
                var z = x % y;
                x = y;
                y = z;
            }
            return s / x * t;
        }



        static void Main(string[] args)
        {
            var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);

            var input = Reads();
            var n = input[0];
            var a = new long[n];
            for (int i = 0; i < n; i++)
            {
                a[i] = Read();
            }
           
            var data = new long[n][];
          
            
        
            Array.Sort(a);
            data[0] = new long[2];
            data[0][0] = a[0];
            data[0][1]=1;
            var j = 0;
            for (int i = 1; i < n; i++)
            {
                data[i] = new long[2];
                if (a[i - 1] == a[i])
                {
                    data[j][1]++;
                }
                else
                {
                    j++;
                    data[j][0] = a[i];
                    data[j][1] = 1;
                }
            }
          
           
     
            long ans = 0;
            for (int i = 0; i < n; i++)
            {
                if (data[i][1]%2==1)
                {
                    ans++;
                }
            }
            Console.WriteLine(ans);

            Console.Out.Flush();
        }
    }
}