One; after reflecting in the twilight on the merit of the previous bulb.
or
Vitamin sea.
or
Just one, provided there is a programmer around to explain how to do it.
or
He doesn't have a heart.
or
A trombone.
or
To hide in a bag of M&M's.
or
Thoreau editing Thorough.
or
Those who read binary and those who don't.
or
Twenty. One to hold the bulb, two to turn the ladder, and 17 to be on the guest list.
or
The eyebrows replied, "no, we are just browsing"
or