-ol -th bbb bbh bbl bbo bbt bhb bhh bhl bho bht blb blh bll blo blt bob boh bol boo bot btb bth btl bto btt hbb hbh hbl hbo hbt hhb hhh hhl hho hht hlb hlh hll hlo hlt hob hoh hol hoo hot htb hth htl hto htt lbb lbh lbl lbo lbt lhb lhh lho lht llb lll llo llt lob loh lol loo lot ltb lth ltl lto ltt ob- obb obh obl obo obt ohh ohl oho oht olb oll olo olt oo- oob ooh ool ooo oot ot- otb oth otl oto ott tbb tbh tbl tbo tbt th- thb thh thl tho tht tlh tll tlo tlt to- tob toh tol too tot ttb tth ttl tto ttt