-er c-- ccc cce ccg ccp ccr ccs ce- cec cee ceg cep cer ces cgc cge cgg cgp cgr cgs cpc cpe cpg cpp cpr cps crc cre crg crp crr crs csc cse csg csp csr css ec- ecc ece ecg ecr ecs eec eee eeg eep eer ees egc ege egg egp egr egs ep- epc epe epg epp epr eps erc ere erg erp err ers es- esc ese esg esp esr ess g-p gcc gce gcg gcp gcr gcs ge- gec gee geg gep ger ges ggc ggg ggp ggr ggs gpc gpe gpg gpp gpr gps grc gre grg grp grr grs gsc gse gsg gsp gsr gss p-p pcc pce pcg pcp pcr pcs pec pee peg pep per pes pgc pge pgg pgp pgr pgs ppc ppe ppg ppp ppr pps prc pre prg prp prr prs ps- psc pse psg psp psr pss rcc rce rcg rcp rcr rcs re- rec ree reg rep rer res rgc rge rgg rgp rgr rgs rpc rpe rpg rpp rpr rps rrc rrg rrp rrr rrs rsc rse rsg rsp rsr rss scc sce scg scp scr scs se- sec see seg sep ser ses sgc sge sgg sgp sgr sgs spc spe spg spp spr sps sr- src sre srg srp srr srs ss- ssc sse ssg ssp ssr sss