public  class numberIndex
    {
 
       public  int this[int number]
        {
            get
            {
                switch(number)
                {
                    case 0:
                        return number;
                    case 1:
                        return 1 + 1;
                    default:
                        return -1;
 
                }
            }
        }
    }

class Program
    {
        static void Main(string[] args)
        {
            numberIndex number = new numberIndex();
            Console.WriteLine(number[3]+"\t"+number[1]+"\t"+number[0]);
            Console.ReadLine();
        }
    }