Stop

using System;

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

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

        int innerCount = 0;
        for (int i = 0; i < n; i++)
        {
            innerCount = 2 * (n + i) - 1;
            Console.WriteLine("{0}//{1}\\\\{0}",
                new string('.', n - i),
                new string('_', innerCount));
        }

        Console.WriteLine("//{0}STOP!{0}\\\\",
            new string('_', (innerCount - 5) / 2 + 1));

        innerCount += 2;
        for (int i = n; i > 0; i--)
        {
            Console.WriteLine("{0}\\\\{1}//{0}",
                new string('.', n - i),
                new string('_', innerCount - 2 * (n - i)));
        }
    }
}