A garbage truck.
or
Thoreau editing Thorough.
or
Stairs.
or
Seven. One to change it and the other six to sing about how good the old one was.
or
Five. Four to decide which way the bulb ought to turn, and . . .
or
ICE ICE Baby......
or
Only one. But he'll leave a big puddle of spit on the floor underneath him.
or