-er a-a a-c a-t aaa aac aae aaf aag aak aao aar aat ac- aca acc ace acf acg ack aco acr act aea aec aee aef aeg aek aeo aer aet af- afa afc afe aff afg afk afo afr aft ag- aga agc age agf agg agk ago agr agt aka akc ake akg akk ako akr aoa aoc aoe aof aog aok aoo aor aot ar- ara arc are arf arg ark aro arr art at- ata atc ate atf atg ato atr att c-- caa cac cae caf cag cak cao car cat cca ccc cce ccf ccg cck cco ccr cct ce- cea cec cee cef ceg cek ceo cer cet cfa cfc cfe cff cfg cfk cfo cfr cft cga cgc cge cgg cgo cgr cgt cka ckc cko ckt co- coa coc coe cof cog cok coo cor cot cra crc cre crf crg crk cro crr crt cta ctc cte ctf ctg ctk cto ctr ctt eaa eac eae eaf eag eak eao ear eat ec- eca ecc ece ecf ecg eck eco ecr ect eea eec eee eef eeg eek eeo eer eet ef- efa efc efe eff efg efo efr eft ega egc ege egf egg ego egr egt eka ekc eke ekf ekg eko ekr ekt eo- eoa eoc eoe eof eog eok eoo eor eot era erc ere erf erg erk ero err ert eta etc ete etf etg etk eto etr ett faa fac fae faf fag fak fao far fat fca fcc fce fcf fcg fck fco fcr fct fea fec fee fef feg fek feo fer fet ffa ffc ffe fff ffg ffk ffo ffr fft fga fgc fge fgf fgg fgr fgt fka fkc fkf fkg fkk fkt foa foc foe fof fog fok foo for fot fra frc fre frf frg frk fro frr frt fta ftc fte ftf ftg ftk fto ftr ftt gaa gac gae gaf gag gak gao gar gat gca gcc gce gcf gcg gck gco gcr gct ge- gea gec gee gef geg gek geo ger get gfa gfc gfe gff gfk gfo gfr gft gga ggc ggg ggo ggr ggt gka gko gkt goa goc goe gof gog gok goo gor got gra grc gre grf grg grk gro grr grt gta gtc gte gtf gtg gtk gto gtr gtt k-t ka- kaa kac kae kaf kag kak kao kar kat kca kcc kce kcg kck kcr kct ke- kea kec kee kef keg kek keo ker ket kfa kfc kff kfg kfo kga kgc kgf kgo kkc kke kkk kkr kkt koa koc koe kof kog kok koo kor kot kra krc krf krg krk kro krr krt kta ktc kte ktf ktg ktk kto ktr ktt oaa oac oae oaf oag oak oao oar oat oc- oca occ ocf ocg ock 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 oka okc oke okg okk oko okr oo- ooa ooc oof oog ook ooo oor oot or- ora orc ore orf org ork oro orr ort ot- ota otc ote otf otg otk oto otr ott ra- raa rac rae raf rag rak rao rar rat rca rcc rce rcf rcg rco rcr rct re- rea rec ree ref reg rek reo rer ret rfa rfc rfe rff rfg rfk rfo rfr rft rga rgc rge rgf rgg rgk rgo rgr rgt rkc rke rkf rkg rkk rko rkt roa roc roe rof rog rok roo ror rot rra rrc rrf rrg rrk rrr rrt rta rtc rte rtf rtg rtk rto rtr rtt taa tac tae taf tag tak tao tar tat tca tcc tce tcf tcg tck tco tcr tct te- tea tec tee tef teg tek teo ter tet tfa tfc tfe tff tfg tfk tfo tfr tft tga tgc tge tgf tgg tgk tgo tgr tgt tka tkc tke tkg tkk tko tkr tkt to- toa toc toe tof tog tok too tor tot tra trc tre trf trg trk tro trr trt tta ttc tte ttf ttg ttk tto ttr ttt