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

namespace yuki
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            string[] s = Console.ReadLine().Split();
            int cnt = 0;

            foreach (var item in s)
            {
                var Q = from word in s
                        where word == item
                        select word;
                if (Q.Count()==1)
                {
                    cnt++;
                }
            }

            Console.WriteLine(cnt);
        }
    }
}