1
17 12
#################
#.###.#.#######.#
#...#...........#
#.#.#.#.###.###.#
#.#.#.#.#.#.#.#.#
#.#.#.###.###.#.#
#.#.#.........#.#
#.#####.#######.#
#...#.#.#.....#.#
#.###.#####.###.#
#...............#
#################
Edit: apologies, previous labyrinth was invalid - “The labyrinth is designed in such a way that there is exactly one path between any two free blocks”