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

class yc2
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        int cout = 0;
        string[] str1 = Console.ReadLine().Split();
        
        for(int i=0;i<str1.Length;i++)
        {
            int j;
            for (j = 0; j < str1.Length; j++)
            {
                if (i != j && str1[i] == str1[j])
                {
                    break;
                }
                
            }
            if (str1.Length == j) cout++;
        }
        Console.WriteLine(cout);
    }
}