-er -ol bbb bbe bbk bbl bbm bbo bbr bbs be- beb bee bek bel bem beo ber bes bkb bke bkk bkl bkm bko bkr bks blb ble blk bll blm blo blr bls bmb bme bmk bml bmm bmo bmr bms bob boe bok bol bom boo bor bos brb bre brk brl brm bro brr brs bsb bse bsk bsl bsm bso bsr bss ebb ebe ebk ebl ebm ebo ebr ebs eeb eee eek eel eem eeo eer ees ekb eke ekl eko ekr eks elb ele elk ell elm elo elr els em- emb eme emk eml emm emo emr ems eo- eob eoe eok eol eom eoo eor eos erb ere erk erl erm ero err ers es- esb ese esk esl esm eso esr ess kbb kbe kbk kbl kbm kbo kbr kbs ke- keb kee kek kel kem keo ker kes kkb kke kkk kkl kkm kkr kks kl- klb klm klo klr kls kmb kme kmk kml kmm kmo kms kob koe kok kol kom koo kor kos krk krl kro krr krs ksb kse ksk ksl ksm kso ksr kss lbb lbe lbk lbl lbm lbo lbr lbs leb lee lek lel lem leo ler les lkb lkl lkr lks llb lle llk lll llm llo llr lls lmb lme lmk lml lmm lmo lmr lms lob loe lok lol lom loo lor los lrb lrk lrm lro lrr lrs lsb lse lsk lsl lsm lso lsr lss m-o m-r mbb mbe mbk mbl mbm mbo mbr mbs meb mee mek mel mem meo mer mes mkb mke mkk mkl mkm mko mkr mks mlb mle mlk mll mlm mlo mlr mls mmb mme mmk mml mmm mmo mmr mms mob moe mok mol mom moo mor mos mrb mre mrk mrl mrm mro mrr mrs msb mse msk msl msm mso msr mss ob- obb obe obk obl obm obo obr obs oeb oee oel oem oeo oer oes okb oke okk okl oko okr oks olb ole olk oll olm olo ols om- omb ome oml omm omo omr oms oo- oob ook ool oom ooo oor oos or- orb ore ork orl orm oro orr ors os- osb ose osk osl osm oso osr oss rbb rbe rbk rbl rbm rbo rbr rbs re- reb ree rek rel rem reo rer res rkb rke rkk rkm rko rks rle rll rlm rlo rlr rls rmb rme rml rmm rmo rmr rms rob roe rok rol rom roo ror ros rrb rrk rrl rrm rrr rrs rsb rse rsk rsl rsm rso rsr rss sbb sbe sbk sbl sbm sbo sbr sbs se- seb see sek sel sem seo ser ses sk- skb ske skk skl skm sko skr sks slb sle slk sll slm slo slr sls smb sme smk sml smm smo smr sms sob soe sok sol som soo sor sos sr- srb sre srk srl srm sro srr srs ss- ssb sse ssk ssl ssm sso ssr sss