using System;

public class HollowSquare

{

    public static void Main()

    {

        int size = Convert.ToInt32(Console.ReadLine());

        if (size<1)

            {

                size =1;

            }

        else if (size>20)

            {

                size =20;

            }

​

        for (int i=0; i<size;i++)

        {

            Console.Write("*");

        }

        Console.WriteLine();

        for(int j=0;j<size-2;j++)

        {

            Console.Write("*");

            for(int k=0;k<size-2;k++)

            {

                Console.Write(" ");

            }

            Console.Write("*");

            Console.WriteLine();

        }

        for (int s=0; s<size;s++)

        {

            Console.Write("*");

        }

    }

}