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

class Program
{
    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();
        string wkStr;
        while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        int[] AArr = InputList[1].Split(' ').Select(X => int.Parse(X)).ToArray();
        Console.WriteLine(AArr.GroupBy(X => X).Count(X => X.Count() == 1));
    }
}