"[[[aq,f],b],[c,d]]"
(0, (1, 9)) (1, (2, 7)) (2, (3, 5)) (3, (a, 4, 4)) (4, (q, 6, 6)) (5, (f, 6, 6)) (6, (8, 8)) (7, (b, 8, 8)) (8, (13, 13)) (9, (10, 11)) (10, (c, 12, 12)) (11, (d, 12, 12)) (12, (13, 13)) (13, (0, 0)) (14, (0, 0))