One, if it knows its own Goedel number.
or
Stop bugging me!
or
One -- but it's an 8 hour minimum.
or
The neutron says "Are you sure?" The proton replies "I'm positive."
or
When it came time to pay, the skunk didn't have a scent, the deer didn't have a buck so they put the meal on the duck's bill.
or
At the crystal ball.
or
Only two, but the hard part is getting them into the light bulb.
or
Weeeeeeeeeeeeeeeeeeeeeeeeeee
or
There are skid marks in front of the skunk.
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Five. One to screw it in and four to tell him how bitchin' he looked doing it.
or