bbb bbi bbo bbr bbs bi- bib bii bio bir bis biz bob boi boo bor bos boz brb bri bro brr brs brz bsb bsi bso bsr bss bzo bzr bzs bzz ibb ibi ibo ibr ibs ibz iib iii iio iir iis io- iob ioi ioo ior ios ir- irb iri iro irr irs is- isb isi iso isr iss izi izo izz o-i ob- obb obi obo obr obs oib oii oio oir ois oiz oo- oob ooi ooo oor oos or- orb ori oro orr ors orz os- osb osi oso osr oss ozo ozs ozz rbb rbi rbo rbr rbs rib rii rio rir ris riz rob roi roo ror ros roz rrb rri rrr rrs rsb rsi rso rsr rss rzb rzo sbb sbi sbo sbr sbs sib sii sio sir sis sob soi soo sor sos soz sr- srb sri sro srr srs ss- ssb ssi sso ssr sss ssz szi szr zbb zbr zbs zib zio zir zis ziz zo- zob zoi zoo zor zos zro zrs zsi zsz zzr zzs zzz