import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        for (int i =0; i<n;i++){
            if (i==0 || i==n-1){
                System.out.print("*".repeat(n));
            }
            else {
                System.out.print("*"+" ".repeat(n-2)+"*");
            }
            System.out.println();
        }
    }
}