Background A polyomino is called L-convex, if it's possible to travel from any tile to any other tile by an L-shaped path, that is, a path that goes in the cardinal directions and changes direction at most once. For example, the polyomino of 1s in the figure 0 0 1 1 1 0 1 1 1 1 0 0 1 1 0 0 0 ...