-er -ol bbb bbe bbf bbg bbl bbo bbr bbs be- beb bee bef beg bel beo ber bes bfb bfe bff bfg bfl bfo bfr bfs bgb bge bgf bgg bgl bgo bgr bgs blb ble blf blg bll blo blr bls bob boe bof bog bol boo bor bos brb bre brf brg brl bro brr brs bsb bse bsf bsg bsl bso bsr bss ebb ebe ebf ebg ebl ebo ebr ebs eeb eee eef eeg eel eeo eer ees ef- efb efe eff efg efl efo efr efs egb ege egf egg egl ego egr egs elb ele elf elg ell elo elr els eo- eob eoe eof eog eol eoo eor eos erb ere erf erg erl ero err ers es- esb ese esf esg esl eso esr ess fbb fbe fbf fbg fbl fbo fbr fbs feb fee fef feg fel feo fer fes ffe fff ffg ffl ffo ffr ffs fgb fge fgf fgg fgl fgr fgs flb fle flf flg fll flo flr fls fob foe fof fog fol foo for fos frb fre frf frg frl fro frr frs fsb fse fsf fsg fsl fso fsr fss gbe gbf gbg gbl gbo gbr gbs ge- geb gee gef geg gel geo ger ges gfb gfe gff gfl gfo gfr gfs ggb ggg ggo ggr ggs glb gle glf glg gll glo glr gls gob goe gof gog gol goo gor gos grb gre grf grg grl gro grr grs gsb gse gsf gsg gsl gso gsr gss lbb lbe lbf lbg lbl lbo lbr lbs leb lee lef leg lel leo ler les lfb lfe lff lfg lfl lfo lfr lfs lgb lge lgf lgg lgl lgo lgr lgs llb lle llf llg lll llo llr lls lob loe lof log lol loo lor los lrb lrf lrg lro lrr lrs lsb lse lsf lsg lsl lso lsr lss ob- obb obe obf obg obl obo obr obs oeb oee oef oeg oel oeo oer oes of- ofb ofe off ofg ofl ofo ofr ofs oge ogf ogg ogl ogo ogs olb ole olf olg oll olo ols oo- oob oof oog ool ooo oor oos or- orb ore orf org orl oro orr ors os- osb ose osf osg osl oso osr oss rbb rbe rbf rbg rbl rbo rbr rbs re- reb ree ref reg rel reo rer res rfb rfe rff rfg rfl rfo rfr rfs rgb rge rgf rgg rgo rgr rgs rle rlf rlg rll rlo rlr rls rob roe rof rog rol roo ror ros rrb rrf rrg rrl rrr rrs rsb rse rsf rsg rsl rso rsr rss sbb sbe sbf sbg sbl sbo sbr sbs se- seb see sef seg sel seo ser ses sfb sfe sff sfg sfl sfo sfr sfs sgb sge sgf sgg sgl sgo sgr sgs slb sle slf slg sll slo slr sls sob soe sof sog sol soo sor sos sr- srb sre srf srg srl sro srr srs ss- ssb sse ssf ssg ssl sso ssr sss