-er a-a a-c a-t aaa aac aae aaf aag aar aas aat ac- aca acc ace acf acg acr acs act aea aec aee aef aeg aer aes aet af- afa afc afe aff afg afr afs aft ag- aga agc age agf agg agr ags agt ar- ara arc are arf arg arr ars art as- asa asc ase asf asg asr ass ast at- ata atc ate atf atg atr ats att c-- caa cac cae caf cag car cas cat cca ccc cce ccf ccg ccr ccs cct ce- cea cec cee cef ceg cer ces cet cfa cfc cfe cff cfg cfr cfs cft cga cgc cge cgg cgr cgs cgt cra crc cre crf crg crr crs crt csa csc cse csf csg csr css cst cta ctc cte ctf ctg ctr cts ctt eaa eac eae eaf eag ear eas eat ec- eca ecc ece ecf ecg ecr ecs ect eea eec eee eef eeg eer ees eet ef- efa efc efe eff efg efr efs eft ega egc ege egf egg egr egs egt era erc ere erf erg err ers ert es- esa esc ese esf esg esr ess est eta etc ete etf etg etr ets ett faa fac fae faf fag far fas fat fca fcc fce fcf fcg fcr fcs fct fea fec fee fef feg fer fes fet ffa ffc ffe fff ffg ffr ffs fft fga fgc fge fgf fgg fgr fgs fgt fra frc fre frf frg frr frs frt fsa fsc fse fsf fsg fsr fss fst fta ftc fte ftf ftg ftr fts ftt gaa gac gae gaf gag gar gas gat gca gcc gce gcf gcg gcr gcs gct ge- gea gec gee gef geg ger ges get gfa gfc gfe gff gfr gfs gft gga ggc ggg ggr ggs ggt gra grc gre grf grg grr grs grt gsa gsc gse gsf gsg gsr gss gst gta gtc gte gtf gtg gtr gts gtt ra- raa rac rae raf rag rar ras rat rca rcc rce rcf rcg rcr rcs rct re- rea rec ree ref reg rer res ret rfa rfc rfe rff rfg rfr rfs rft rga rgc rge rgf rgg rgr rgs rgt rra rrc rrf rrg rrr rrs rrt rsa rsc rse rsf rsg rsr rss rst rta rtc rte rtf rtg rtr rts rtt saa sac sae saf sag sar sas sat sca scc sce scf scg scr scs sct se- sea sec see sef seg ser ses set sfa sfc sfe sff sfg sfr sfs sft sga sgc sge sgf sgg sgr sgs sgt sr- sra src sre srf srg srr srs srt ss- ssa ssc sse ssf ssg ssr sss sst sta stc ste stf stg str sts stt taa tac tae taf tag tar tas tat tca tcc tce tcf tcg tcr tcs tct te- tea tec tee tef teg ter tes tet tfa tfc tfe tff tfg tfr tfs tft tga tgc tge tgf tgg tgr tgs tgt tra trc tre trf trg trr trs trt tsa tsc tse tsf tsg tsr tss tst tta ttc tte ttf ttg ttr tts ttt