-er a-a a-c aaa aac aae aag aap aar ac- aca acc ace acg acp acr aea aec aee aeg aep aer ag- aga agc age agg agp agr ap- apa apc ape apg app apr ar- ara arc are arg arp arr c-- caa cac cae cag cap car cca ccc cce ccg ccp ccr ce- cea cec cee ceg cep cer cga cgc cge cgg cgp cgr cpa cpc cpe cpg cpp cpr cra crc cre crg crp crr eaa eac eae eag eap ear ec- eca ecc ece ecg ecr eea eec eee eeg eep eer ega egc ege egg egp egr ep- epa epc epe epg epp epr era erc ere erg erp err g-p gaa gac gae gag gap gar gca gcc gce gcg gcp gcr ge- gea gec gee geg gep ger gga ggc ggg ggp ggr gpa gpc gpe gpg gpp gpr gra grc gre grg grp grr p-p paa pac pae pag pap par pca pcc pce pcg pcp pcr pea pec pee peg pep per pga pgc pge pgg pgp pgr ppa ppc ppe ppg ppp ppr pra prc pre prg prp prr ra- raa rac rae rag rap rar rca rcc rce rcg rcp rcr re- rea rec ree reg rep rer rga rgc rge rgg rgp rgr rpa rpc rpe rpg rpp rpr rra rrc rrg rrp rrr