03.01 Illuminati Lock

using System;
public class IlluminatiLock
{
    public static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        int length = 3 * n;
        int height = n + 2;

        for (int i = 0; i < height; i++)
        {
            if (i == 0 || i == height - 1)
            {
                string side = new string('.', n);
                string middle = new string('#', n);
                Console.WriteLine("{0}{1}{0}", side, middle);
            }
            else if (i < height / 2)
            {
                int edgeSpace = n - (2 * i);
                int midspace = n - 2;
                int sideSpace = (length - (2 * edgeSpace) - 6 - midspace) / 2;
                string edge = new string('.', edgeSpace);
                string middle = new string('.', midspace);
                string side = new string('.', sideSpace);
                Console.WriteLine("{0}##{1}#{2}#{1}##{0}", edge, side, middle);
            }
            else if (i > height / 2)
            {
                int edgeSpace = n - ((height - i - 1) * 2);
                int midspace = n - 2;
                int sideSpace = (length - (2 * edgeSpace) - 6 - midspace) / 2;
                string edge = new string('.', edgeSpace);
                string middle = new string('.', midspace);
                string side = new string('.', sideSpace);
                Console.WriteLine("{0}##{1}#{2}#{1}##{0}", edge, side, middle);
            }
        }
    }
}