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.Collections.Generic;
using System.IO;
using System.Linq;
using static ABC073_20200315C.Input;

namespace ABC073_20200315C
{
    class Input
    {
        /// <summary>
        /// 1行の文字列の入力
        /// </summary>
        public static void @in(out string s)
        {
            s = String();
        }

        private static String String()
        {
            return Console.ReadLine();
        }

        /// <summary>
        /// 複数行の文字列の入力
        /// </summary>
        public static void @in(long rowNumber, out string[] s)
        {
            s = new String[rowNumber];
            for (long i = 0; i < rowNumber; i++) @in(out s[i]);
        }

        /// <summary>
        /// 1行に書かれた1つの整数の入力
        /// </summary>
        public static void @in(out int i)
        {
            i = int.Parse(String());
        }

        /// <summary>
        /// 1行に書かれた1つの整数の入力
        /// </summary>
        public static void @in(out long a)
        {
            a = Long()[0];
        }

        /// <summary>
        /// 1行に書かれた2つの整数の入力
        /// </summary>
        public static void @in(out long a, out long b)
        {
            long[] lArr = Long();
            a = lArr[0];
            b = lArr[1];
        }

        /// <summary>
        /// 1行に書かれた3つの整数の入力
        /// </summary>
        public static void @in(out long a, out long b, out long c)
        {
            long[] lArr = Long();
            a = lArr[0];
            b = lArr[1];
            c = lArr[2];
        }

        /// <summary>
        /// 1行に書かれた4つの整数の入力
        /// </summary>
        public static void @in(out long a, out long b, out long c, out long d)
        {
            long[] lArr = Long();
            a = lArr[0];
            b = lArr[1];
            c = lArr[2];
            d = lArr[3];
        }

        /// <summary>
        /// 1行に書かれた5つの整数の入力
        /// </summary>
        public static void @in(out long a, out long b, out long c, out long d, out long e)
        {
            long[] lArr = Long();
            a = lArr[0];
            b = lArr[1];
            c = lArr[2];
            d = lArr[3];
            e = lArr[4];
        }

        private static long[] Long()
        {
            return Split().Select(long.Parse).ToArray();
        }

        /// <summary>
        /// 1行に書かれた複数の整数列の入力
        /// </summary>
        public static void @in(out long[] lArr)
        {
            lArr = Long();
        }

        /// <summary>
        /// rowNumber行に書かれた1つの整数列の入力
        /// </summary>
        public static void @in(long rowNumber, out long[] lArr)
        {
            lArr = new long[rowNumber];
            for (long i = 0; i < rowNumber; i++) @in(out lArr[i]);
        }

        /// <summary>
        /// rowNumber行に書かれた2つの整数列の入力
        /// </summary>
        public static void @in(long rowNumber, out long[] a, out long[] b)
        {
            a = new long[rowNumber];
            b = new long[rowNumber];
            for (int i = 0; i < rowNumber; i++) @in(out a[i], out b[i]);
        }

        /// <summary>
        /// rowNumber行に書かれた3つの整数列の入力
        /// </summary>
        public static void @in(long rowNumber, out long[] a, out long[] b, out long[] c)
        {
            a = new long[rowNumber];
            b = new long[rowNumber];
            c = new long[rowNumber];
            for (int i = 0; i < rowNumber; i++) @in(out a[i], out b[i], out c[i]);
        }

        /// <summary>
        /// rowNumber行に書かれた4つの整数列の入力
        /// </summary>
        public static void @in(long rowNumber, out long[] a, out long[] b, out long[] c, out long[] d)
        {
            a = new long[rowNumber];
            b = new long[rowNumber];
            c = new long[rowNumber];
            d = new long[rowNumber];
            for (int i = 0; i < rowNumber; i++) @in(out a[i], out b[i], out c[i], out d[i]);
        }

        /// <summary>
        /// h行w列の整数の行列の入力
        /// </summary>
        public static void @in(long h, long w, out long[][] a)
        {
            a = new long[h][];
            for (long i = 0; i < h; i++) @in(out a[i]);
        }

        /// <summary>
        /// 1行に書かれた1つの小数の入力
        /// </summary>
        public static void @in(out double d)
        {
            d = double.Parse(String());
        }

        /// <summary>
        /// 1行に書かれた小数の配列の入力
        /// </summary>
        public static void @in(out double[] dArr)
        {
            dArr = Split().Select(double.Parse).ToArray();
        }

        private static IEnumerable<string> Split()
        {
            return String().Split(' ');
        }
    }

    class Program
    {
        public static void Main(string[] args)
        {
            StreamWriter streamWriter = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false};
            Console.SetOut(streamWriter);
            new Solver().Solve();
            Console.Out.Flush();
        }

        public static void Debug()
        {
            new Solver().Solve();
        }
    }

    class Solver
    {
        private long N;
        private long[] A;

        public void Solve()
        {
            @in(out N);
            @in(N, out A);

            HashSet<long> paper = new HashSet<long>();
            for (int i = 0; i < N; i++)
            {
                if (paper.Contains(A[i])) paper.Remove(A[i]);
                else
                {
                    paper.Add(A[i]);
                }
            }

            Console.WriteLine(paper.Count);
        }
    }
}