Trapezoid

using System;
//Write a program that prints on the console the border of a trapezoid by given number N.
//The width of the top side of the trapezoid must be exactly N.
//The width of the bottom side of the trapezoid must be exactly 2 * N.
//The height of the trapezoid must be exactly N + 1.
//Also the top right and the bottom right angle of the trapezoid must be equal to 90 degrees.

class Program
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        for (int j = 0; j < n+1; j++)
        {
            for (int i = 0; i < 2 * n; i++)
            {
                if (j == 0) //first row
                {
                    if (i + n >= 2 * n)
                    {
                        Console.Write("*");
                    }
                    else
                    {
                        Console.Write(".");
                    }
                }
                if (j == n) //last row
                {
                    Console.Write("*");
                }
                else if(j > 0) //mid rows
                {
                    if (i == n - j || i == 2 * n - 1)
                    {
                        Console.Write("*");
                    }
                    else
                    {
                        Console.Write(".");
                    }

                }
            }
            Console.WriteLine();
        }
    }
}