Стоп ;Чертане Фиг Цикли

using System;
using System.Runtime.InteropServices;

namespace Калинка
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int w = n * 4 + 3;

            Console.Write("{0}{1}{0}",
                              new string('.', n + 1),
                              new string('_', 2 * n + 1));
            Console.WriteLine();

            for (int i = 1; i <= n; i++)
            {
                var dots = n + 1 - i;
                var lower = w - dots * 2 - 4;

                Console.Write("{0}//{1}\\\\{0}",
                              new string('.', dots),
                              new string('_', lower));
                Console.WriteLine();
            }

            var lowerMid = (w - 9) / 2;
            Console.WriteLine("//{0}STOP!{0}\\\\",
                          new string('_', lowerMid));

            for (int i = 0; i < n; i++)
            {
                var dots = 0 + i;
                var lower = w - dots * 2 - 4;

                Console.Write("{0}\\\\{1}//{0}",
                              new string('.', dots),
                              new string('_', lower));
                Console.WriteLine();
            }
        }
    }
}

//                   СТОП

//                  4
//                  ....._________.....
//                  ....//_______\\....
//                  ...//_________\\...
//                  ..//___________\\..
//                  .//_____________\\.
//                  //_____STOP!_____\\
//                  \\_______________//
//                  .\\_____________//.
//                  ..\\___________//..
//                  ...\\_________//...