let dimension x =

    for i=1 to x do

        for i=1 to x do
            print_string("+--")
        done;

        print_string("+");

        print_newline();

        for i=1 to x do
            print_string("+ "^string_of_int(i))
        done;

        print_string("+");

        print_newline();

    done;

    for i=1 to x do
        print_string("+--")
    done;

    print_string("+");

;;