bbb bbi bbk bbo bbt bi- bib bii bik bio bit bkb bkk bko bkt bob boi bok boo bot btb bti btk bto btt ibb ibi ibk ibo ibt iib iii iio iit ikb iki ikk iko ikt io- iob ioi ioo iot itb iti itk ito itt k-t kbb kbi kbk kbo kib kii kik kio kit kkb kki kkk kkt kob koi kok koo kot ktb ktk kto ktt o-i ob- obb obi obk obo obt oib oii oik oio oit okb oki okk oko oo- oob ooi ook ooo oot ot- otb oti otk oto ott tbb tbi tbk tbo tbt tib tii tik tio tit tkb tkk tko tkt to- tob toi tok too tot ttb tti ttk tto ttt