Reading this maze
Narrow arcade starts at row 3, column 4. Of the 30 grid positions, 20 are paintable and 10 are walls. The start is already painted; the other 19 tiles remain to be reached.
Start up from row 3, column 4. The wall stops you at row 2, column 4; keep the side corridors available for a return visit. The first slide covers 2 of 20 target tiles; 18 remain.
The verified opening crosses 1 tiles before stopping. A breadth-first search proves a 15-slide finish from this exact starting board; that is a reference target, not a move limit. You may revisit any painted tile.
