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

namespace foryuki
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            string[] s = Console.ReadLine().Split();
            var dic = new Dictionary<string, string>();
            var li = new List<string>();

            for (int i = 0; i < N; i++)
            {
                if (dic.ContainsKey(s[i]))
                {
                    li.Add(s[i]);
                }
                else
                {
                    dic.Add(s[i], s[i]);
                }
            }

            foreach (var item in li)
            {
                dic.Remove(item);
            }

            Console.WriteLine(dic.Count);
        }


        //-------------------------------------------------------------

        static int[] ConvertStringArrayToIntArray(string[] str)
        {
            int[] b = Array.ConvertAll<string, int>(str, delegate(string value)
                {
                    return int.Parse(value);
                });
            return b;
        }

        static List<int> ConvertStringArrayToIntList(string[] str)
        {
            var list = new List<int>();
            foreach (var c in str)
            {
                list.Add(int.Parse(c));
            }
            return list;
        }
    }
}