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

class Program
{
    static void Main(string[] args)
    {
        int N = int.Parse(Console.ReadLine());
        long[] A = Console.ReadLine().Split(' ').Select(s => long.Parse(s)).ToArray();

        Array.Sort(A);

        int ans = 0;

        if (A.Count(x => x == A[0]) == 1) { ans++; }
        for (int i = 1; i < N; i++)
        {
            if (A[i - 1] == A[i]) { continue; }
            if (A.Count(x => x == A[i]) == 1) { ans++; }
        }
        Console.WriteLine(ans);
    }
}