-er a-a a-c aaa aac aae aag aak aap aar aas ac- aca acc ace acg ack acp acr acs aea aec aee aeg aek aep aer aes ag- aga agc age agg agk agp agr ags aka akc ake akg akk akp akr aks ap- apa apc ape apg apk app apr aps ar- ara arc are arg ark arp arr ars as- asa asc ase asg ask asp asr ass c-- caa cac cae cag cak cap car cas cca ccc cce ccg cck ccp ccr ccs ce- cea cec cee ceg cek cep cer ces cga cgc cge cgg cgp cgr cgs cka ckc cks cpa cpc cpe cpg cpk cpp cpr cps cra crc cre crg crk crp crr crs csa csc cse csg csk csp csr css eaa eac eae eag eak eap ear eas ec- eca ecc ece ecg eck ecr ecs eea eec eee eeg eek eep eer ees ega egc ege egg egp egr egs eka ekc eke ekg ekp ekr eks ep- epa epc epe epg epp epr eps era erc ere erg erk erp err ers es- esa esc ese esg esk esp esr ess g-p gaa gac gae gag gak gap gar gas gca gcc gce gcg gck gcp gcr gcs ge- gea gec gee geg gek gep ger ges gga ggc ggg ggp ggr ggs gka gkp gks gpa gpc gpe gpg gpk gpp gpr gps gra grc gre grg grk grp grr grs gsa gsc gse gsg gsk gsp gsr gss ka- kaa kac kae kag kak kap kar kas kca kcc kce kcg kck kcp kcr kcs ke- kea kec kee keg kek kep ker kes kga kgc kgp kgs kkc kke kkk kkp kkr kks kpa kpc kpe kpk kpp kpr kps kra krc krg krk krp krr krs ksa ksc kse ksg ksk ksp ksr kss p-p paa pac pae pag pak pap par pas pca pcc pce pcg pck pcp pcr pcs pea pec pee peg pek pep per pes pga pgc pge pgg pgk pgp pgr pgs pka pkc pke pkg pkp pkr pks ppa ppc ppe ppg ppk ppp ppr pps pra prc pre prg prk prp prr prs ps- psa psc pse psg psk psp psr pss ra- raa rac rae rag rak rap rar ras rca rcc rce rcg rcp rcr rcs re- rea rec ree reg rek rep rer res rga rgc rge rgg rgk rgp rgr rgs rkc rke rkg rkk rkp rks rpa rpc rpe rpg rpk rpp rpr rps rra rrc rrg rrk rrp rrr rrs rsa rsc rse rsg rsk rsp rsr rss saa sac sae sag sak sap sar sas sca scc sce scg sck scp scr scs se- sea sec see seg sek sep ser ses sga sgc sge sgg sgk sgp sgr sgs sk- ska skc ske skg skk skp skr sks spa spc spe spg spk spp spr sps sr- sra src sre srg srk srp srr srs ss- ssa ssc sse ssg ssk ssp ssr sss