-er a-a a-c a-t aaa aac aae aaf aag aao aar aas aat ac- aca acc ace acf acg aco acr acs act aea aec aee aef aeg aeo aer aes aet af- afa afc afe aff afg afo afr afs aft ag- aga agc age agf agg ago agr ags agt aoa aoc aoe aof aog aoo aor aos aot ar- ara arc are arf arg aro arr ars art as- asa asc ase asf asg aso asr ass ast at- ata atc ate atf atg ato atr ats att c-- caa cac cae caf cag cao car cas cat cca ccc cce ccf ccg cco ccr ccs cct ce- cea cec cee cef ceg ceo cer ces cet cfa cfc cfe cff cfg cfo cfr cfs cft cga cgc cge cgg cgo cgr cgs cgt co- coa coc coe cof cog coo cor cos cot cra crc cre crf crg cro crr crs crt csa csc cse csf csg cso csr css cst cta ctc cte ctf ctg cto ctr cts ctt eaa eac eae eaf eag eao ear eas eat ec- eca ecc ece ecf ecg eco ecr ecs ect eea eec eee eef eeg eeo eer ees eet ef- efa efc efe eff efg efo efr efs eft ega egc ege egf egg ego egr egs egt eo- eoa eoc eoe eof eog eoo eor eos eot era erc ere erf erg ero err ers ert es- esa esc ese esf esg eso esr ess est eta etc ete etf etg eto etr ets ett faa fac fae faf fag fao far fas fat fca fcc fce fcf fcg fco fcr fcs fct fea fec fee fef feg feo fer fes fet ffa ffc ffe fff ffg ffo ffr ffs fft fga fgc fge fgf fgg fgr fgs fgt foa foc foe fof fog foo for fos fot fra frc fre frf frg fro frr frs frt fsa fsc fse fsf fsg fso fsr fss fst fta ftc fte ftf ftg fto ftr fts ftt gaa gac gae gaf gag gao gar gas gat gca gcc gce gcf gcg gco gcr gcs gct ge- gea gec gee gef geg geo ger ges get gfa gfc gfe gff gfo gfr gfs gft gga ggc ggg ggo ggr ggs ggt goa goc goe gof gog goo gor gos got gra grc gre grf grg gro grr grs grt gsa gsc gse gsf gsg gso gsr gss gst gta gtc gte gtf gtg gto gtr gts gtt oaa oac oae oaf oag oao oar oas oat oc- oca occ ocf ocg oco ocr ocs oct oea oec oee oef oeg oeo oer oes oet of- ofa ofc ofe off ofg ofo ofr ofs oft oga ogc oge ogf ogg ogo ogs ogt oo- ooa ooc oof oog ooo oor oos oot or- ora orc ore orf org oro orr ors ort os- osa osc ose osf osg oso osr oss ost ot- ota otc ote otf otg oto otr ots ott ra- raa rac rae raf rag rao rar ras rat rca rcc rce rcf rcg rco rcr rcs rct re- rea rec ree ref reg reo rer res ret rfa rfc rfe rff rfg rfo rfr rfs rft rga rgc rge rgf rgg rgo rgr rgs rgt roa roc roe rof rog roo ror ros rot rra rrc rrf rrg rrr rrs rrt rsa rsc rse rsf rsg rso rsr rss rst rta rtc rte rtf rtg rto rtr rts rtt saa sac sae saf sag sao sar sas sat sca scc sce scf scg sco scr scs sct se- sea sec see sef seg seo ser ses set sfa sfc sfe sff sfg sfo sfr sfs sft sga sgc sge sgf sgg sgo sgr sgs sgt soa soc soe sof sog soo sor sos sot sr- sra src sre srf srg sro srr srs srt ss- ssa ssc sse ssf ssg sso ssr sss sst sta stc ste stf stg sto str sts stt taa tac tae taf tag tao tar tas tat tca tcc tce tcf tcg tco tcr tcs tct te- tea tec tee tef teg teo ter tes tet tfa tfc tfe tff tfg tfo tfr tfs tft tga tgc tge tgf tgg tgo tgr tgs tgt to- toa toc toe tof tog too tor tos tot tra trc tre trf trg tro trr trs trt tsa tsc tse tsf tsg tso tsr tss tst tta ttc tte ttf ttg tto ttr tts ttt