-th bbb bbh bbk bbo bbt bhb bhh bhk bho bht bkb bkk bko bkt bob boh bok boo bot btb bth btk bto btt hbb hbh hbk hbo hbt hhb hhh hhk hho hht hkb hkh hkk hko hkt hob hoh hok hoo hot htb hth htk hto htt k-t kbb kbh kbk kbo khh khk kho kkb kkh kkk kkt kob koh kok koo kot ktb kth ktk kto ktt ob- obb obh obk obo obt ohh oho oht okb okk oko oo- oob ooh ook ooo oot ot- otb oth otk oto ott tbb tbh tbk tbo tbt th- thb thh thk tho tht tkb tkk tko tkt to- tob toh tok too tot ttb tth ttk tto ttt