-er a-a a-c a-t aaa aac aae aaf aag aao aar aat ac- aca acc ace acf acg aco acr act aea aec aee aef aeg aeo aer aet af- afa afc afe aff afg afo afr aft ag- aga agc age agf agg ago agr agt aoa aoc aoe aof aog aoo aor aot ar- ara arc are arf arg aro arr art at- ata atc ate atf atg ato atr att c-- caa cac cae caf cag cao car cat cca ccc cce ccf ccg cco ccr cct ce- cea cec cee cef ceg ceo cer cet cfa cfc cfe cff cfg cfo cfr cft cga cgc cge cgg cgo cgr cgt co- coa coc coe cof cog coo cor cot cra crc cre crf crg cro crr crt cta ctc cte ctf ctg cto ctr ctt eaa eac eae eaf eag eao ear eat ec- eca ecc ece ecf ecg eco ecr ect eea eec eee eef eeg eeo eer eet ef- efa efc efe eff efg efo efr eft ega egc ege egf egg ego egr egt eo- eoa eoc eoe eof eog eoo eor eot era erc ere erf erg ero err ert eta etc ete etf etg eto etr ett faa fac fae faf fag fao far fat fca fcc fce fcf fcg fco fcr fct fea fec fee fef feg feo fer fet ffa ffc ffe fff ffg ffo ffr fft fga fgc fge fgf fgg fgr fgt foa foc foe fof fog foo for fot fra frc fre frf frg fro frr frt fta ftc fte ftf ftg fto ftr ftt gaa gac gae gaf gag gao gar gat gca gcc gce gcf gcg gco gcr gct ge- gea gec gee gef geg geo ger get gfa gfc gfe gff gfo gfr gft gga ggc ggg ggo ggr ggt goa goc goe gof gog goo gor got gra grc gre grf grg gro grr grt gta gtc gte gtf gtg gto gtr gtt oaa oac oae oaf oag oao oar oat oc- oca occ ocf ocg oco ocr oct oea oec oee oef oeg oeo oer oet of- ofa ofc ofe off ofg ofo ofr oft oga ogc oge ogf ogg ogo ogt oo- ooa ooc oof oog ooo oor oot or- ora orc ore orf org oro orr ort ot- ota otc ote otf otg oto otr ott ra- raa rac rae raf rag rao rar rat rca rcc rce rcf rcg rco rcr rct re- rea rec ree ref reg reo rer ret rfa rfc rfe rff rfg rfo rfr rft rga rgc rge rgf rgg rgo rgr rgt roa roc roe rof rog roo ror rot rra rrc rrf rrg rrr rrt rta rtc rte rtf rtg rto rtr rtt taa tac tae taf tag tao tar tat tca tcc tce tcf tcg tco tcr tct te- tea tec tee tef teg teo ter tet tfa tfc tfe tff tfg tfo tfr tft tga tgc tge tgf tgg tgo tgr tgt to- toa toc toe tof tog too tor tot tra trc tre trf trg tro trr trt tta ttc tte ttf ttg tto ttr ttt