Figure.Trapezoid

using System;
class Trapezoid
{
    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());

            Console.WriteLine("{0}{1}",new string('.', n),new string('*', n));

            int outputDots = n-1;
            int stars = 1;
            int innerDots = n-1;

            for (int i = 0; i < n - 1; i++)
            {
                Console.Write(new string('.', outputDots));
                Console.Write(new string('*', stars));
                Console.Write(new string('.', innerDots));
                Console.Write(new string('*', stars));

                outputDots--;
                innerDots++;

                Console.WriteLine();
            }
            Console.WriteLine(new string('*', n * 2));
        }
    }