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

namespace Programming
{
    class Program
    {
        static void Main(string[] args)
        {
            //入力
            int N = int.Parse(Console.ReadLine());
            string[] str = Console.ReadLine().Split(' ');
            int[] A = new int[N];
            for (int i = 0; i < N; i++)
            {
                A[i] = int.Parse(str[i]);
            }
            //----------------------------------------------
            int cnt;
            int cnt2 = 0;

            for (int i = 0; i < N; i++)
            {
                cnt = 0;
                for (int j = 0; j < N; j++)
                {
                    if (A[i] == A[j])
                    {
                        cnt++;
                        if (cnt == 2)
                        {
                            break;
                        }
                    }
                }
                if (cnt == 1)
                {
                    cnt2++;
                }
            }

            Console.WriteLine(cnt2);
        }
    }
}