-er bbb bbe bbi bbk bbo bbr bbt be- beb bee bei bek beo ber bet bez bi- bib bie bii bik bio bir bit biz bkb bke bkk bko bkr bkt bob boe boi bok boo bor bot boz brb bre bri brk bro brr brt brz btb bte bti btk bto btr btt btz bze bzo bzr bzz ebb ebe ebi ebk ebo ebr ebt eeb eee eek eeo eer eet eib eie eii eik eio eir eit ekb eke eki eko ekr ekt eo- eob eoe eoi eok eoo eor eot erb ere eri erk ero err ert erz etb ete eti etk eto etr ett etz eze ezo ezr ezz ibb ibe ibi ibk ibo ibr ibt ibz ie- iee iei iek ier iet iib iie iii iio iir iit ikb ike iki ikk iko ikr ikt io- iob ioe ioi ioo ior iot ir- irb ire iri irk iro irr irt itb ite iti itk ito itt itz ize izi izo izz k-t k-z kbb kbe kbi kbk kbo kbr kbz ke- keb kee kei kek keo ker ket kez kib kie kii kik kio kir kit kiz kkb kke kki kkk kkr kkt kob koe koi kok koo kor kot koz kri krk kro krr krt ktb kte ktk kto ktr ktt kzo o-i ob- obb obe obi obk obo obr obt oeb oee oei oeo oer oet oib oie oii oik oio oir oit oiz okb oke oki okk oko okr oo- oob ooi ook ooo oor oot or- orb ore ori ork oro orr ort orz ot- otb ote oti otk oto otr ott otz oze ozo ozt ozz rbb rbe rbi rbk rbo rbr rbt re- reb ree rei rek reo rer ret rez rib rie rii rik rio rir rit riz rkb rke rkk rko rkt rkz rob roe roi rok roo ror rot roz rrb rri rrk rrr rrt rtb rte rti rtk rto rtr rtt rtz rzb rze rzo tbb tbe tbi tbk tbo tbr tbt tbz te- teb tee tei tek teo ter tet tez tib tie tii tik tio tir tit tiz tkb tke tkk tko tkr tkt tkz to- tob toe toi tok too tor tot toz trb tre tri trk tro trr trt trz ttb tte tti ttk tto ttr ttt tze zbb zbr zbt zeb zee zek zeo zer zet zez zib zie zik zio zir zit ziz zo- zob zoe zoi zok zoo zor zot zro zte ztr zzr zzt zzz