06.SquareOfStars

using System;

class Program
{
    static void Main()
    {
        var n = int.Parse(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));
    }
}