IlluminatiLock

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


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

        int width = 3 * n;
        int height = n + 1;

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

        int secondPart = n - 2;

        Console.WriteLine("{0}###{1}###{0}",
            new string('.', secondPart),
            new string('.', secondPart),
            new string('.', secondPart));

        int thirdPartRows = (n - 3) / 2;
        int thirdPart = n - 4;
        int thirdPart2 = 2;



        for (int i = 0; i < thirdPartRows; i++)
        {
            Console.WriteLine("{0}##{1}#{2}#{1}##{0}",
            new string('.', thirdPart),
            new string('.', thirdPart2),
            new string('.', secondPart),
            new string('.', thirdPart2),
            new string('.', thirdPart));

            thirdPart -= 2;
            thirdPart2 += 2;

        }

        int fourthPartRows = (n - 3) / 2;
        int fourthPart = 1;
        int fourthPart2 = n - 3;

        for (int i = 0; i < fourthPartRows; i++)
        {
            Console.WriteLine("{0}##{1}#{2}#{1}##{0}",
            new string('.', fourthPart),
            new string('.', fourthPart2),
            new string('.', secondPart),
            new string('.', fourthPart2),
            new string('.', fourthPart));

            fourthPart += 2;
            fourthPart2 -= 2;

        }

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

        //int secondPart = n - 2;

        Console.WriteLine("{0}###{1}###{0}",
            new string('.', secondPart),
            new string('.', secondPart),
            new string('.', secondPart));

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

    }
}