using System;

public class Program

{public static void Main()

{int taille = 20; //taille du sablier en nombre pair

​

            for (int i = 0; i <= taille / 2; i++)

            {

                for (int j = 0; j < i; j++)

                {

                    Console.Write(" ");

                }

                for (int j = i; j <= taille-i; j++)

                {

                    Console.Write("*");

                }

                Console.WriteLine();

            }

            for (int i = 0; i <= taille / 2; i++)

            {

                int nbEspace = taille / 2 - i;

                for (int j = 0; j < nbEspace; j++)

                {

                    Console.Write(" ");

                }

                for (int j = 0; j <= 2 * i; j++)

                {

                    Console.Write("*");

                }

                Console.WriteLine();

            }

            Console.WriteLine();

            Console.WriteLine();

            Console.WriteLine();

            Console.WriteLine();

}

}