Example problem:

The deck measures 16 units by 16 units. There are 10 containers, in
three classes:

A          B         C
6x8        4x4       4x8
4x6        4x4       4x8
4x4        4x6       4x6
                     4x6

Containers of classes B and C are constrained to be at least 4 units
apart in at least one of the north-south or east-west directions.