One, but only if the lightbulb really to change.
A: Thousands because Confucious say many hands make light work.
One. They stick the bulb in the socket and wait for the world to revolve around them!
By holding the bulb up to the socket and waiting for the world to revolve around them.
Apparently not 8
The patients are the ones who eventually get better and get to go home.
A psychiatric tryst.