When Spider Man invented his wall-climbing machine, everyone thought it wouldn't work. They were right! Quite simply, there was nothing to hold the machine onto the wall. But how much of a screwbrain was Spidey? Did he at least manage to get the wheels that were in contact with the wall (A and B) to turn the right way? The inside of the machine is shown above with pulleys (black) and cogs (white).
Which way do wheels A and B rotate?