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

public class Hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        string[] line = Console.ReadLine().Trim().Split(' ');
        var a = Array.ConvertAll(line, int.Parse);
        var d = new Dictionary<int, int>();
        for (int i = 0; i < n; i++)
            if (d.ContainsKey(a[i])) d[a[i]]++;
            else d[a[i]] = 1;
        Console.WriteLine(d.Count(x => x.Value == 1));
    }
}