Пеперуда

using System;

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

           for (int i = 1; i <= n - 2; i++)
            {
               if (i % 2 != 0)
                {
                    int topStarsCount = n - 2;
                    string topStars = new string('*', topStarsCount);
                    Console.WriteLine($"{topStars}\\ /{topStars}");
                }
                else
                {
                    int topdashCount = n - 2;
                    string topdash = new string('-', topdashCount);
                    Console.WriteLine($"{topdash}\\ /{topdash}");
                }
            }
            //        ..... MIDLE UP

            int midSpacesCount = n - 1;
            string midSpaces = new string(' ', midSpacesCount);
            Console.WriteLine($"{midSpaces}@");

            //        ..... MIDLE DOWN

            for (int i = 1; i <= n - 2; i++)
            {
                if (i % 2 != 0)
                {
                    int topStarsCount = n - 2;
                    string topStars = new string('*', topStarsCount);
                    Console.WriteLine($"{topStars}/ \\{topStars}");
                }
                else
                {
                    int topdashCount = n - 2;
                    string topdash = new string('-', topdashCount);
                    Console.WriteLine($"{topdash}/ \\{topdash}");
                }
            }

        }
    }
}