-er a-a a-b a-t aaa aab aae aag aao aar aas aat ab- aba abb abe abg abo abr abs abt aea aeb aee aeg aeo aer aes aet ag- aga agb age agg ago agr ags agt aoa aob aoe aog aoo aor aos aot ar- ara arb are arg aro arr ars art as- asa asb ase asg aso asr ass ast at- ata atb ate atg ato atr ats att baa bab bae bag bao bar bas bat bba bbb bbe bbg bbo bbr bbs bbt be- bea beb bee beg beo ber bes bet bga bgb bge bgg bgo bgr bgs bgt boa bob boe bog boo bor bos bot bra brb bre brg bro brr brs brt bsa bsb bse bsg bso bsr bss bst bta btb bte btg bto btr bts btt eaa eab eae eag eao ear eas eat eba ebb ebe ebg ebo ebr ebs ebt eea eeb eee eeg eeo eer ees eet ega egb ege egg ego egr egs egt eo- eoa eob eoe eog eoo eor eos eot era erb ere erg ero err ers ert es- esa esb ese esg eso esr ess est eta etb ete etg eto etr ets ett gaa gab gae gag gao gar gas gat gba gbe gbg gbo gbr gbs gbt ge- gea geb gee geg geo ger ges get gga ggb ggg ggo ggr ggs ggt goa gob goe gog goo gor gos got gra grb gre grg gro grr grs grt gsa gsb gse gsg gso gsr gss gst gta gtb gte gtg gto gtr gts gtt oaa oab oae oag oao oar oas oat ob- oba obb obe obg obo obr obs obt oea oeb oee oeg oeo oer oes oet oga oge ogg ogo ogs ogt oo- ooa oob oog ooo oor oos oot or- ora orb ore org oro orr ors ort os- osa osb ose osg oso osr oss ost ot- ota otb ote otg oto otr ots ott ra- raa rab rae rag rao rar ras rat rba rbb rbe rbg rbo rbr rbs rbt re- rea reb ree reg reo rer res ret rga rgb rge rgg rgo rgr rgs rgt roa rob roe rog roo ror ros rot rra rrb rrg rrr rrs rrt rsa rsb rse rsg rso rsr rss rst rta rtb rte rtg rto rtr rts rtt saa sab sae sag sao sar sas sat sba sbb sbe sbg sbo sbr sbs sbt se- sea seb see seg seo ser ses set sga sgb sge sgg sgo sgr sgs sgt soa sob soe sog soo sor sos sot sr- sra srb sre srg sro srr srs srt ss- ssa ssb sse ssg sso ssr sss sst sta stb ste stg sto str sts stt taa tab tae tag tao tar tas tat tba tbb tbe tbg tbo tbr tbs tbt te- tea teb tee teg teo ter tes tet tga tgb tge tgg tgo tgr tgs tgt to- toa tob toe tog too tor tos tot tra trb tre trg tro trr trs trt tsa tsb tse tsg tso tsr tss tst tta ttb tte ttg tto ttr tts ttt