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

namespace SortItems
{
    class Program
    {
        static void Main(string[] args)
        {
            var n = int.Parse(Console.ReadLine());
            var nums = Console.ReadLine().Split().Select(int.Parse).ToArray();
            Array.Sort(nums);
            var d = new Dictionary<int, int>();

            for (var i = 0; i < n; i++)
            {
                if (d.ContainsKey(nums[i]))
                {
                    d[nums[i]]++;
                }
                else
                {
                    d[nums[i]] = 1;
                }
            }

            Console.WriteLine(d.Count(x => x.Value == 1));

        }
    }
}