int num, r, c, H = 0;



            char ds;



            Random rnd = new Random();







            do

            {



                Console.WriteLine("Scrivi un numero compreso tra 1 e 20");



                num = Convert.ToInt16(Console.ReadLine());



            }



            while (num > 20 | num < 0);







            for (r = 1; r <= num; r++) //incremento

            {



                for (c = num + 1 - (r + 1); c >= 0; c--)

                {

                    Console.ForegroundColor = ConsoleColor.Cyan;

                    Console.Write("-");



                }



                for (c = 1; c <= r; c++)

                {



                    H = rnd.Next(1, 10);



                    if (H < 2)

                    {

                        Console.ForegroundColor = ConsoleColor.Red;

                        ds = '*';



                    }



                    else if (H < 9)

                    {

                        Console.ForegroundColor = ConsoleColor.Green;

                        ds = 'o';



                    }



                    else

                    {

                        Console.ForegroundColor = ConsoleColor.Yellow;

                        ds = 'x';



                    }



                    Console.Write(ds);



                }



                for (c = 1; c < r; c++)

                {



                    H = rnd.Next(1, 10);



                    if (H < 2)

                    {

                        Console.ForegroundColor = ConsoleColor.Red;

                        ds = '*';



                    }



                    else if (H < 9)

                    {

                        Console.ForegroundColor = ConsoleColor.Green;

                        ds = 'o';



                    }



                    else

                    {

                        Console.ForegroundColor = ConsoleColor.Yellow;

                        ds = 'x';



                    }



                    Console.Write(ds);



                }



                for (c = num + 1 - (r + 1); c >= 0; c--)

                {

                    Console.ForegroundColor = ConsoleColor.Cyan;

                    Console.Write("-");



                }



                Console.WriteLine();

            }



            for (int t = 1; t <= (num / 4); t++) //tronco

            {

                for (c = num + 1 - (r + 1); c > 0; c--)

                {

                    Console.ForegroundColor = ConsoleColor.Cyan;

                    Console.Write("-");

                }

                for (r = 1; r < num; r++)

                {

                    Console.ForegroundColor = ConsoleColor.Cyan;

                    Console.Write("-");

                }



                    Console.ForegroundColor = ConsoleColor.DarkYellow;

                    Console.Write("888");



                for (r = 1; r < num; r++)

                {

                    Console.ForegroundColor = ConsoleColor.Cyan;

                    Console.Write("-");

                }

                Console.WriteLine();

            }



            Console.ReadLine();