-er bbb bbd bbe bbi bbk bbo bbr bbs bdb bdd bde bdi bdk bdo bdr bds be- beb bed bee bei bek beo ber bes bi- bib bid bie bii bik bio bir bis bkb bke bkk bko bkr bks bob bod boe boi bok boo bor bos brb brd bre bri brk bro brr brs bsb bsd bse bsi bsk bso bsr bss dbb dbd dbe dbi dbk dbo dbr dbs ddb ddd dde ddi ddk ddo ddr dds de- deb ded dee dei dek deo der des di- dib did die dii dik dio dir dis dkb dke dki dkk dko dkr dks dob dod doe doi dok doo dor dos drb drd dre dri drk dro drr drs dsb dsd dse dsi dsk dso dsr dss ebb ebd ebe ebi ebk ebo ebr ebs ed- edb edd ede edi edk edo edr eds eeb eed eee eek eeo eer ees eib eid eie eii eik eio eir eis ekb ekd eke eki eko ekr eks eo- eob eod eoe eoi eok eoo eor eos erb erd ere eri erk ero err ers es- esb esd ese esi esk eso esr ess i-d ibb ibd ibe ibi ibk ibo ibr ibs idb idd ide idi idk ido idr ids ie- ied iee iei iek ier ies iib iid iie iii iio iir iis ikb ike iki ikk iko ikr iks io- iob iod ioe ioi ioo ior ios ir- irb ird ire iri irk iro irr irs is- isb isd ise isi isk iso isr iss kbb kbd kbe kbi kbk kbo kbr kbs kdb kde kdk kdo kdr kds ke- keb ked kee kei kek keo ker kes kib kid kie kii kik kio kir kis kkb kke kki kkk kkr kks kob kod koe koi kok koo kor kos krd kri krk kro krr krs ksb ksd kse ksi ksk kso ksr kss o-i ob- obb obd obe obi obk obo obr obs odb odd ode odi odo odr ods oeb oed oee oei oeo oer oes oib oid oie oii oik oio oir ois okb okd oke oki okk oko okr oks oo- oob ood ooi ook ooo oor oos or- orb ord ore ori ork oro orr ors os- osb osd ose osi osk oso osr oss rbb rbd rbe rbi rbk rbo rbr rbs rdb rdd rde rdi rdo rdr rds re- reb red ree rei rek reo rer res rib rid rie rii rik rio rir ris rkb rke rkk rko rks rob rod roe roi rok roo ror ros rrb rrd rri rrk rrr rrs rsb rsd rse rsi rsk rso rsr rss sbb sbd sbe sbi sbk sbo sbr sbs sdb sdd sde sdi sdk sdo sdr sds se- seb sed see sei sek seo ser ses sib sid sie sii sik sio sir sis sk- skb skd ske ski skk sko skr sks sob sod soe soi sok soo sor sos sr- srb srd sre sri srk sro srr srs ss- ssb ssd sse ssi ssk sso ssr sss