-er -ol bbb bbd bbe bbk bbl bbo bbr bbs bdb bdd bde bdk bdl bdo bdr bds be- beb bed bee bek bel beo ber bes bkb bke bkk bkl bko bkr bks blb bld ble blk bll blo blr bls bob bod boe bok bol boo bor bos brb brd bre brk brl bro brr brs bsb bsd bse bsk bsl bso bsr bss dbb dbd dbe dbk dbl dbo dbr dbs ddb ddd dde ddk ddl ddo ddr dds de- deb ded dee dek del deo der des dkb dke dkk dkl dko dkr dks dl- dlb dld dle dlk dll dlo dlr dls dob dod doe dok dol doo dor dos drb drd dre drk drl dro drr drs dsb dsd dse dsk dsl dso dsr dss ebb ebd ebe ebk ebl ebo ebr ebs ed- edb edd ede edk edl edo edr eds eeb eed eee eek eel eeo eer ees ekb ekd eke ekl eko ekr eks elb eld ele elk ell elo elr els eo- eob eod eoe eok eol eoo eor eos erb erd ere erk erl ero err ers es- esb esd ese esk esl eso esr ess kbb kbd kbe kbk kbl kbo kbr kbs kdb kde kdk kdl kdo kdr kds ke- keb ked kee kek kel keo ker kes kkb kke kkk kkl kkr kks kl- klb kld klo klr kls kob kod koe kok kol koo kor kos krd krk krl kro krr krs ksb ksd kse ksk ksl kso ksr kss lbb lbd lbe lbk lbl lbo lbr lbs ldb ldd lde ldk ldl ldo ldr lds leb led lee lek lel leo ler les lkb lkl lkr lks llb lld lle llk lll llo llr lls lob lod loe lok lol loo lor los lrb lrd lrk lro lrr lrs lsb lsd lse lsk lsl lso lsr lss ob- obb obd obe obk obl obo obr obs odb odd ode odl odo odr ods oeb oed oee oel oeo oer oes okb okd oke okk okl oko okr oks olb old ole olk oll olo ols oo- oob ood ook ool ooo oor oos or- orb ord ore ork orl oro orr ors os- osb osd ose osk osl oso osr oss rbb rbd rbe rbk rbl rbo rbr rbs rdb rdd rde rdl rdo rdr rds re- reb red ree rek rel reo rer res rkb rke rkk rko rks rld rle rll rlo rlr rls rob rod roe rok rol roo ror ros rrb rrd rrk rrl rrr rrs rsb rsd rse rsk rsl rso rsr rss sbb sbd sbe sbk sbl sbo sbr sbs sdb sdd sde sdk sdl sdo sdr sds se- seb sed see sek sel seo ser ses sk- skb skd ske skk skl sko skr sks slb sld sle slk sll slo slr sls sob sod soe sok sol soo sor sos sr- srb srd sre srk srl sro srr srs ss- ssb ssd sse ssk ssl sso ssr sss