-er c-- ccc cce ccg cck cco ccr ccs ce- cec cee ceg cek ceo cer ces cgc cge cgg cgo cgr cgs ckc cko cks co- coc coe cog cok coo cor cos crc cre crg crk cro crr crs csc cse csg csk cso csr css ec- ecc ece ecg eck eco ecr ecs eec eee eeg eek eeo eer ees egc ege egg ego egr egs ekc eke ekg eko ekr eks eo- eoc eoe eog eok eoo eor eos erc ere erg erk ero err ers es- esc ese esg esk eso esr ess gcc gce gcg gck gco gcr gcs ge- gec gee geg gek geo ger ges ggc ggg ggo ggr ggs gko gks goc goe gog gok goo gor gos grc gre grg grk gro grr grs gsc gse gsg gsk gso gsr gss kcc kce kcg kck kcr kcs ke- kec kee keg kek keo ker kes kgc kgo kgs kkc kke kkk kkr kks koc koe kog kok koo kor kos krc krg krk kro krr krs ksc kse ksg ksk kso ksr kss oc- occ ocg ock oco ocr ocs oec oee oeg oeo oer oes ogc oge ogg ogo ogs okc oke okg okk oko okr oks oo- ooc oog ook ooo oor oos or- orc ore org ork oro orr ors os- osc ose osg osk oso osr oss rcc rce rcg rco rcr rcs re- rec ree reg rek reo rer res rgc rge rgg rgk rgo rgr rgs rkc rke rkg rkk rko rks roc roe rog rok roo ror ros rrc rrg rrk rrr rrs rsc rse rsg rsk rso rsr rss scc sce scg sck sco scr scs se- sec see seg sek seo ser ses sgc sge sgg sgk sgo sgr sgs sk- skc ske skg skk sko skr sks soc soe sog sok soo sor sos sr- src sre srg srk sro srr srs ss- ssc sse ssg ssk sso ssr sss