-er a-a a-c aaa aac aae aag aar aas ac- aca acc ace acg acr acs aea aec aee aeg aer aes ag- aga agc age agg agr ags ar- ara arc are arg arr ars as- asa asc ase asg asr ass c-- caa cac cae cag car cas cca ccc cce ccg ccr ccs ce- cea cec cee ceg cer ces cga cgc cge cgg cgr cgs cra crc cre crg crr crs csa csc cse csg csr css eaa eac eae eag ear eas ec- eca ecc ece ecg ecr ecs eea eec eee eeg eer ees ega egc ege egg egr egs era erc ere erg err ers es- esa esc ese esg esr ess gaa gac gae gag gar gas gca gcc gce gcg gcr gcs ge- gea gec gee geg ger ges gga ggc ggg ggr ggs gra grc gre grg grr grs gsa gsc gse gsg gsr gss ra- raa rac rae rag rar ras rca rcc rce rcg rcr rcs re- rea rec ree reg rer res rga rgc rge rgg rgr rgs rra rrc rrg rrr rrs rsa rsc rse rsg rsr rss saa sac sae sag sar sas sca scc sce scg scr scs se- sea sec see seg ser ses sga sgc sge sgg sgr sgs sr- sra src sre srg srr srs ss- ssa ssc sse ssg ssr sss