Square_of_Stars

using System;

namespace Square_of_Stars
{
    class Square_of_Stars
{
        static void Main(string[] args)
        {
            var N = int.Parse(Console.ReadLine());
            for (int i = 1; i <= N; i++)
            {
                for (int j = 1; j <= N; j++)
                {
                    if ((i != 1) && (i != N) && (j != 1) && (j != N))
                    {
                        Console.Write(" ");
                    }
                    else
                    {
                        Console.Write("*");
                    }
                }
                Console.WriteLine();
            }
        }
    }
}