A set of electronic cards must be plugged into racks with electric connectors. Different types of racks can hold different sets of cards, incurring different costs. Given a set of cards and a maximal number of racks to use, you must find a set of (at most) the given number of racks to fit in all the cards, while you hold the cost to a minimum.

A rack has the following features:

For cards, consider only the power they use.