A few years ago there appeared on the commercial market a certain puzzle called “Maestro”. This consists of packing into a 6 x 10 rectangle the twelve shapes depicted in Fig. 1, (where they are shown packed into an annular region bounded by two concentric squares). It is also possible to pack these shapes into other simple geometrical figures. The aesthetic attraction of this problem lies in the fact that the twelve shapes concerned form a complete set in the sense that any other shape consisting of five abutting squares is congruent to one of them.