-er -ic a-a a-c a-i aaa aac aae aag aai aar aas ac- aca acc ace acg aci acr acs aea aec aee aeg aei aer aes ag- aga agc age agg agi agr ags ai- aia aic aie aig aii air ais ar- ara arc are arg ari arr ars as- asa asc ase asg asi asr ass c-- caa cac cae cag cai car cas cca ccc cce ccg cci ccr ccs ce- cea cec cee ceg cei cer ces cga cgc cge cgg cgi cgr cgs ci- cia cic cie cig cii cir cis cra crc cre crg cri crr crs csa csc cse csg csi csr css eaa eac eae eag eai ear eas ec- eca ecc ece ecg eci ecr ecs eea eec eee eeg eer ees ega egc ege egg egi egr egs eia eic eie eig eii eir eis era erc ere erg eri err ers es- esa esc ese esg esi esr ess gaa gac gae gag gai gar gas gca gcc gce gcg gci gcr gcs ge- gea gec gee geg gei ger ges gga ggc ggg ggi ggr ggs gia gic gie gig gii gir gis gra grc gre grg gri grr grs gsa gsc gse gsg gsi gsr gss ia- iaa iac iae iag iai iar ias ica icc ice icg ici icr ics ie- iea iec iee ieg iei ier ies iga igc ige igg igi igr igs iia iic iie iii iir iis ir- ira irc ire irg iri irr irs is- isa isc ise isg isi isr iss ra- raa rac rae rag rai rar ras rca rcc rce rcg rci rcr rcs re- rea rec ree reg rei rer res rga rgc rge rgg rgi rgr rgs ria ric rie rig rii rir ris rra rrc rrg rri rrr rrs rsa rsc rse rsg rsi rsr rss saa sac sae sag sai sar sas sca scc sce scg sci scr scs se- sea sec see seg sei ser ses sga sgc sge sgg sgi sgr sgs sia sic sie sig sii sir sis sr- sra src sre srg sri srr srs ss- ssa ssc sse ssg ssi ssr sss