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

namespace lecture2018._1._15
{
    class Program
    {
        static void Main(string[] args)
        {
            string line = Console.ReadLine();
            int N = int.Parse(line);

            line = Console.ReadLine();

            string[] hoge = line.Split();

            int[] Num = new int[N];
            for(int i = 0;i < N;i++)
            {
                Num[i] = int.Parse(hoge[i]);
            }

            Dictionary<int, int> counts = new Dictionary<int,int>();
            for(int i = 0;i < N;i++)
            {
                if (counts.ContainsKey(Num[i])){
                    counts[Num[i]] += 1;
                }
                else
                {
                    counts[Num[i]] = 1;
                }
            }
            int ans = 0;
            foreach (int key in counts.Keys)
            {
                if (counts[key] == 1)
                {
                    ans++;
                }
            }

            Console.WriteLine(ans);
        }
    }
}