bbb bbi bbk bbo bbr bi- bib bii bik bio bir biz bkb bkk bko bkr bob boi bok boo bor boz brb bri brk bro brr brz bzo bzr bzz ibb ibi ibk ibo ibr ibz iib iii iio iir ikb iki ikk iko ikr io- iob ioi ioo ior ir- irb iri irk iro irr izi izo izz k-z kbb kbi kbk kbo kbr kbz kib kii kik kio kir kiz kkb kki kkk kkr kob koi kok koo kor koz kri krk kro krr kzo o-i ob- obb obi obk obo obr oib oii oik oio oir oiz okb oki okk oko okr oo- oob ooi ook ooo oor or- orb ori ork oro orr orz ozo ozz rbb rbi rbk rbo rbr rib rii rik rio rir riz rkb rkk rko rkz rob roi rok roo ror roz rrb rri rrk rrr rzb rzo zbb zbr zib zik zio zir ziz zo- zob zoi zok zoo zor zro zzr zzz