Ace_of_Diamonds

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Problem_3___Ace_of_Diamonds
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());


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

            int rows = n - 2;
            int first = (n - 3) / 2;
            int first2 = (n - 1) / 2;
            int first3 = 1;

            for (int i = 0; i < first2; i++)
            {
                if (n == 3)
                {
                    Console.WriteLine("*@*");
                    continue;
                }
                Console.WriteLine("*{0}{1}{0}*",
                    new string('-', first),
                    new string('@', first3),
                    new string('-', first));

                first3 += 2;
                first--;

                if (first <=0)
                {
                    first = 0;
                }
            }

            int second2 = 1;
            int second = n - 4;
            int secondRow = first2 - 1;

            for (int i = 0; i < secondRow; i++)
            {
                Console.WriteLine("*{0}{1}{0}*",
                    new string('-', second2),
                    new string('@', second),
                    new string('-', second2));

                second2++;
                second -= 2;
            }
            Console.WriteLine("{0}", new string('*', n));

        }
    }
}