class Program
    {
        static void Main(string[] args)
        {
            int[] n = Array.ConvertAll(Console.ReadLine().Split(' '), num => int.Parse(num.ToString()));
            int[] cardList = Array.ConvertAll(Console.ReadLine().Split(' '), num => int.Parse(num.ToString()));
            Array.Sort(cardList);
            int count = 1;
            for(int i = 1; i < n[1]; i++)
            {
                if (cardList[i-1] != cardList[i])
                {
                    count++;
                }
            }
            Console.WriteLine(count);
        }
    }