Summertime

using System;

    class Program
    {
        static void Main()
        {

            int n = int.Parse(Console.ReadLine());


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

            for (int i = 1; i <= (n/2)+1; i++)
            {

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

            int counterSpaces = ((2*n)-(n+1))/2;
            int middleSpaces = n-1;


            for (int i = 1; i <= (n/2)-1; i++)
            {
                counterSpaces -= 1;
                middleSpaces  +=2;


                Console.WriteLine("{0}*{1}*{0}", new string (' ', counterSpaces), new string (' ', middleSpaces), new string(' ', counterSpaces ));

            }

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

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


        }
    }