Eggcelent

using System;

class Eggcelent
{
    static void Main()
    {
        int N = int.Parse(Console.ReadLine());
        int height = 2 * N;
        int width = (3 * N) - 1;
        int topHeight = N - 1;
        int bottomHeight = N - 1;
        int outerDots = N;
        int innerSymbols = N - 1;
        int count = 0;

        // print top row
        Console.Write('.');
        Console.Write(new string('.', outerDots));
        Console.Write(new string('*', innerSymbols));
        Console.Write(new string('.', outerDots));
        Console.Write('.');
        Console.WriteLine();

        // print top part
        for (int i = 1; i < topHeight; i++)
        {
            outerDots -= 2;
            if (i == 1) innerSymbols += 2;
            else innerSymbols += 4;
            if (outerDots <= 0)
            {
                outerDots = 0;
                innerSymbols = width - 2;
                count++;
            }

            Console.Write('.');

            Console.Write(new string('.', outerDots));
            Console.Write('*');
            Console.Write(new string('.', innerSymbols));
            Console.Write('*');
            Console.Write(new string('.', outerDots));

            Console.Write('.');
            Console.WriteLine();
        }

        // print ribbon
        for (int i = 0; i < 2; i++)
        {
            Console.Write(".*");
            for (int j = 0; j < width - 2; j++)
            {
                if (i == 0)
                {
                    if (j % 2 == 1) Console.Write('.');
                    else Console.Write('@');
                }
                else
                {
                    if (j % 2 == 1) Console.Write('@');
                    else Console.Write('.');
                }
            }
            Console.Write("*.");
            Console.WriteLine();
        }

        // print bottom part
        outerDots = 0;
        innerSymbols = width - 4;

        for (int i = bottomHeight - 1; i >= 1; i--)
        {
            if (count > 0)
            {
                outerDots = 0;
                innerSymbols = width - 2;
            }
            else
            {
                outerDots += 2;
                innerSymbols -= 4;
            }
            if (outerDots >=  width)
            {
                outerDots = 0;
                innerSymbols = width + 2;
            }

            Console.Write('.');

            Console.Write(new string('.', outerDots));
            Console.Write('*');
            Console.Write(new string('.', innerSymbols));
            Console.Write('*');
            Console.Write(new string('.', outerDots));

            Console.Write('.');
            Console.WriteLine();
            count--;
        }

        // print bottom row
        outerDots = N;
        innerSymbols = N - 1;
        Console.Write('.');
        Console.Write(new string('.', outerDots));
        Console.Write(new string('*', innerSymbols));
        Console.Write(new string('.', outerDots));
        Console.Write('.');
        Console.WriteLine();
    }
}