package hinh_chu_nhat;
import java.util.Scanner;


public class Hinh_Chu_Nhat {


    public static void main(String[] args) {
        Scanner Sc=new Scanner(System.in);
        int a,b;//a dai, b rong
        do
        {
            a=Sc.nextInt();
            b=Sc.nextInt();
            if(a<2||b<2) System.out.print("Nhap lai a va b\n");
        }while(a<2||b<2);
        for(int i=0;i<b;i++)
        {
            for(int j=0;j<a;j++)
            {
                if(j==0||j==(a-1)||i==0||i==(b-1)) System.out.print("#");
                else System.out.print(" ");
            }
            System.out.print("\n");
        }
    }

}