-er a-a a-c aaa aac aae aag aak aan aao aar aas ac- aca acc ace acg ack acn aco acr acs aea aec aee aeg aek aen aeo aer aes ag- aga agc age agg agk agn ago agr ags aka akc ake akg akk akn ako akr aks an- ana anc ane ang ank ann ano anr ans aoa aoc aoe aog aok aon aoo aor aos ar- ara arc are arg ark arn aro arr ars as- asa asc ase asg ask asn aso asr ass c-- caa cac cae cag cak can cao car cas cca ccc cce ccg cck ccn cco ccr ccs ce- cea cec cee ceg cek cen ceo cer ces cga cgc cge cgg cgn cgo cgr cgs cka ckc cko cks cn- cna cnc cne cng cnn cno cnr cns co- coa coc coe cog cok con coo cor cos cra crc cre crg crk crn cro crr crs csa csc cse csg csk csn cso csr css eaa eac eae eag eak ean eao ear eas ec- eca ecc ece ecg eck ecn eco ecr ecs eea eec eee eeg eek een eeo eer ees ega egc ege egg egn ego egr egs eka ekc eke ekg eko ekr eks en- ena enc ene eng enk enn eno enr ens eo- eoa eoc eoe eog eok eon eoo eor eos era erc ere erg erk ern ero err ers es- esa esc ese esg esk esn eso esr ess gaa gac gae gag gak gan gao gar gas gca gcc gce gcg gck gcn gco gcr gcs ge- gea gec gee geg gek gen geo ger ges gga ggc ggg ggn ggo ggr ggs gka gkn gko gks gna gnc gne gnn gno gnr gns goa goc goe gog gok gon goo gor gos gra grc gre grg grk grn gro grr grs gsa gsc gse gsg gsk gsn gso gsr gss ka- kaa kac kae kag kak kan kao kar kas kca kcc kce kcg kck kcn kcr kcs ke- kea kec kee keg kek ken keo ker kes kga kgc kgo kgs kkc kke kkk kkn kkr kks kn- kna knc kne kng knk knn kno knr koa koc koe kog kok kon koo kor kos kra krc krg krk krn kro krr krs ksa ksc kse ksg ksk ksn kso ksr kss naa nac nae nag nak nan nao nar nas nca ncc nce ncg nck ncn nco ncr ncs ne- nea nec nee neg nek nen neo ner nes nga ngc nge ngg ngk ngn ngo ngs nka nkc nke nkk nkn nko nkr nks nna nnc nne nng nnk nnn nno nns no- noa noc noe nog nok non noo nor nos nra nrc nre nrg nrk nrn nro nrr nrs nsa nsc nse nsg nsk nsn nso nsr nss oaa oac oae oag oak oan oao oar oas oc- oca occ ocg ock ocn oco ocr ocs oea oec oee oeg oen oeo oer oes oga ogc oge ogg ogn ogo ogs oka okc oke okg okk oko okr oks on- ona onc one ong onk onn ono onr ons oo- ooa ooc oog ook oon ooo oor oos or- ora orc ore org ork orn oro orr ors os- osa osc ose osg osk osn oso osr oss ra- raa rac rae rag rak ran rao rar ras rca rcc rce rcg rcn rco rcr rcs re- rea rec ree reg rek ren reo rer res rga rgc rge rgg rgk rgn rgo rgr rgs rkc rke rkg rkk rko rks rna rnc rng rnn rno rnr rns roa roc roe rog rok ron roo ror ros rra rrc rrg rrk rrn rrr rrs rsa rsc rse rsg rsk rsn rso rsr rss saa sac sae sag sak san sao sar sas sca scc sce scg sck scn sco scr scs se- sea sec see seg sek sen seo ser ses sga sgc sge sgg sgk sgn sgo sgr sgs sk- ska skc ske skg skk sko skr sks sna snc sne sng snk snn sno snr sns soa soc soe sog sok son soo sor sos sr- sra src sre srg srk srn sro srr srs ss- ssa ssc sse ssg ssk ssn sso ssr sss