Reading this maze
Open courtyard starts at row 1, column 1. Of the 9 grid positions, 8 are paintable and 1 are walls. The start is already painted; the other 7 tiles remain to be reached.
Start right from row 1, column 1. The wall stops you at row 1, column 3; keep the side corridors available for a return visit. The first slide covers 3 of 8 target tiles; 5 remain.
The verified opening crosses 2 tiles before stopping. A breadth-first search proves a 4-slide finish from this exact starting board; that is a reference target, not a move limit. You may revisit any painted tile.
