using System;

public class Program

{

    public static void Main()

    {

        var n = int.Parse(Console.ReadLine());

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

        for(int rows = 0; rows < n-2 ; rows++){

            Console.WriteLine("*" + new string(' ', n-2) + "*");

        }

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

    }

}