Reading this maze
Four landings starts at row 2, column 2. Of the 20 grid positions, 17 are paintable and 3 are walls. The start is already painted; the other 16 tiles remain to be reached.
Start down from row 2, column 2. The wall stops you at row 3, column 2; keep the side corridors available for a return visit. The first slide covers 2 of 17 target tiles; 15 remain.
The verified opening crosses 1 tiles before stopping. A breadth-first search proves a 9-slide finish from this exact starting board; that is a reference target, not a move limit. You may revisit any painted tile.
