using System;

class Squer
{
    static void Main(string[] args)
    {
        var n = int.Parse(Console.ReadLine());
        string line = new string('*', n);
        Console.WriteLine(line);
        for (int i = 2; i < n - 2; i++)
        {
            Console.WriteLine('*' + new string(' ', n - 2) + '*');
        }
        Console.WriteLine(line);
    }
}