let rec print h w =
        let rec print_s w =
                match w with
                |0 -> Printf.printf "\n"
                |_ -> Printf.printf "#";
                print_s (w - 1)
        in
        let rec print_d w =
                let rec print_d_inner w =
                        match w with
                        |0 -> ()
                        |_ -> Printf.printf ".";
                        print_d_inner (w - 1)
                in
                Printf.printf "#";
                print_d_inner (w - 2);
                Printf.printf "#\n"
        in
        let rec print_d_loop n w =
                match n with
                |0 -> ()
                |_ -> print_d w;
                print_d_loop (n - 1) w
        in
        print_s w;
        print_d_loop (h - 2) w;
        print_s w;
        Printf.printf "\n";;

let rec loop () =
        Scanf.scanf "%d %d\n" (fun h w -> if h = 0 && w = 0 then () else (print h w;loop()));;

let () =
        loop ();;