FallenInLove

using System;

namespace FallenInLove
{
	class Program
	{
		public static void Main(string[] args)
		{
			var n = int.Parse(Console.ReadLine());
			var tilda = 1;
			var outerDots = 2 * n;
			var innerDots = 2;
			Console.WriteLine("##{0}##{0}##", new string('.', 2 * n));
			for(var i = 1; i <= n - 1; i++)
			{
				outerDots -= 2;
				Console.WriteLine("#{0}#{1}#{2}#{1}#{0}#", new string('~', tilda), new string('.', outerDots), new string('.', innerDots));
				tilda++;
				innerDots += 2;
			}
			outerDots--;
			Console.WriteLine("{0}#{1}#{2}#{1}#{0}", new string('.', outerDots), new string('~', tilda), new string('.', innerDots));
			tilda++;
			innerDots += 2;
			tilda--;
			innerDots -= 2;
			outerDots += 2;
			for(var i = 1; i <= n - 1; i++)
			{
				tilda--;
				innerDots -= 2;
				Console.WriteLine("{0}#{1}#{2}#{1}#{0}", new string('.', outerDots), new string('~', tilda), new string('.', innerDots));
				outerDots += 2;
			}
			Console.WriteLine("{0}####{0}", new string('.', 2 * n + 1));
			for(var i = 1; i <= n; i++)
			{
				Console.WriteLine("{0}##{0}", new string('.', 2 * n + 2));
			}
			Console.Write("Press any key to continue . . . ");
			Console.ReadKey(true);
		}
	}
}