using System;

public class Program

{

    public static void Main()

    {

        int n,i,j;

        n=Convert.ToInt32(Console.ReadLine());

        for(i=0;i<=n-1;i++)

        {

            for(j=0;j<=n-1;j++)

            {

                if(i==0||i==n-1||j==0||j==n-1)

                {

                    Console.Write("*");

                    Console.Write("\t");

                }

                else

                {

                    Console.Write(".");

                    Console.Write("\t");

                }

            }

            Console.Write("\n");

            }

        }

​

    }

​

​