SquareOfStars

using System;

class Program
{
    static void Main()
    {
        var n = Convert.ToInt32(Console.ReadLine());
        Console.WriteLine(new string('*', n));

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

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