using System;
using System.Text;
using System.Linq;

namespace ConsoleApp11
{
    class Program
    {
        static void Main(string[] args)
        {
            long N = long.Parse(Console.ReadLine());

            long count = 0;

            bool tof = true;

            long[] A = new long[N];

            var input = Console.ReadLine().Split(' ');

            for(long i = 0; i < N; i++)
            {
                A[i] = long.Parse(input[i]);
            }

            for(int i = 0; i < N; i++)
            {
                for(int j = 0; j < N; j++)
                {
                    if(i != j)
                    {
                        if(A[i] == A[j])
                        {
                            tof = false;

                            break;

                            
                        }
                    }
                }
                if(tof == true)
                {
                    count++;
                }

                tof = true;
            }

            Console.WriteLine(count);
        }
    }
}