To get to the other side!
That's impossible, because they can't climb the ladder.
NonononononononononoNONONONONONO! NONONONONONONO! NONONONONONONONONONONONONONONO! (he can't.)
Just two. It only requires that either the people are very small or the light bulb is very large.
I am not sure, I haven't seen them try and I can't do it either.
One.