[Mark Sir Link]

taken from http://code.ign.com/foo

You own a license plate manufacturing company. Write a program that takes a population and determines the simplest pattern that will produce enough unique plates. Since all the plates that match the pattern will be generated, find the pattern that produces the least excess plates. Use a combination of letters (A-Z) and numbers (0-9).

Simplest pattern seems open to interpretation, meaning that a mixture of numbers and letters is probably acceptable, IE, A03B21C, but then all plates must follow that same ordering of letters and numbers

EDIT: AAA-### should yield the same maximum combination of plates as mixing them together. I apologize.