-er -ol bbb bbe bbg bbk bbl bbo bbr bbs be- beb bee beg bek bel beo ber bes bgb bge bgg bgk bgl bgo bgr bgs bkb bke bkg bkk bkl bko bkr bks blb ble blg blk bll blo blr bls bob boe bog bok bol boo bor bos brb bre brg brk brl bro brr brs bsb bse bsg bsk bsl bso bsr bss ebb ebe ebg ebk ebl ebo ebr ebs eeb eee eeg eek eel eeo eer ees egb ege egg egl ego egr egs ekb eke ekg ekl eko ekr eks elb ele elg elk ell elo elr els eo- eob eoe eog eok eol eoo eor eos erb ere erg erk erl ero err ers es- esb ese esg esk esl eso esr ess gbe gbg gbk gbl gbo gbr gbs ge- geb gee geg gek gel geo ger ges ggb ggg ggo ggr ggs gkb gko gks glb gle glg glk gll glo glr gls gob goe gog gok gol goo gor gos grb gre grg grk grl gro grr grs gsb gse gsg gsk gsl gso gsr gss kbb kbe kbk kbl kbo kbr kbs ke- keb kee keg kek kel keo ker kes kgb kgl kgo kgs kkb kke kkk kkl kkr kks kl- klb klg klo klr kls kob koe kog kok kol koo kor kos krg krk krl kro krr krs ksb kse ksg ksk ksl kso ksr kss lbb lbe lbg lbk lbl lbo lbr lbs leb lee leg lek lel leo ler les lgb lge lgg lgk lgl lgo lgr lgs lkb lkg lkl lkr lks llb lle llg llk lll llo llr lls lob loe log lok lol loo lor los lrb lrg lrk lro lrr lrs lsb lse lsg lsk lsl lso lsr lss ob- obb obe obg obk obl obo obr obs oeb oee oeg oel oeo oer oes oge ogg ogl ogo ogs okb oke okg okk okl oko okr oks olb ole olg olk oll olo ols oo- oob oog ook ool ooo oor oos or- orb ore org ork orl oro orr ors os- osb ose osg osk osl oso osr oss rbb rbe rbg rbk rbl rbo rbr rbs re- reb ree reg rek rel reo rer res rgb rge rgg rgk rgo rgr rgs rkb rke rkg rkk rko rks rle rlg rll rlo rlr rls rob roe rog rok rol roo ror ros rrb rrg rrk rrl rrr rrs rsb rse rsg rsk rsl rso rsr rss sbb sbe sbg sbk sbl sbo sbr sbs se- seb see seg sek sel seo ser ses sgb sge sgg sgk sgl sgo sgr sgs sk- skb ske skg skk skl sko skr sks slb sle slg slk sll slo slr sls sob soe sog sok sol soo sor sos sr- srb sre srg srk srl sro srr srs ss- ssb sse ssg ssk ssl sso ssr sss