In the dictionary.
or
Nearly unanswerable, since the one who tries to change it usually drops it, and the others call for a planning session.
or
Humpty Trumpty wants Mexico to pay for it all.
or
1,000,001: One to change the bulb and 1,000,000 to rebuild civilization to the point where they need light bulbs again.
or
None. Bill Gates will just redefine Darkness® as the industry standard.
or