-er a-a a-c a-z aaa aac aae aag aar aas aaz ac- aca acc ace acg acr acs acz aea aec aee aeg aer aes aez ag- aga agc age agg agr ags agz ar- ara arc are arg arr ars arz as- asa asc ase asg asr ass asz az- aza aze azg azs azz c-- caa cac cae cag car cas caz cca ccc cce ccg ccr ccs ccz ce- cea cec cee ceg cer ces cez cga cgc cge cgg cgr cgs cra crc cre crg crr crs crz csa csc cse csg csr css csz cz- czc cze eaa eac eae eag ear eas eaz 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 erz es- esa esc ese esg esr ess eze ezr ezs ezz gaa gac gae gag gar gas gaz gca gcc gce gcg gcr gcs ge- gea gec gee geg ger ges gez gga ggc ggg ggr ggs ggz gra grc gre grg grr grs gsa gsc gse gsg gsr gss gza gzr ra- raa rac rae rag rar ras raz rca rcc rce rcg rcr rcs re- rea rec ree reg rer res rez rga rgc rge rgg rgr rgs rra rrc rrg rrr rrs rsa rsc rse rsg rsr rss rza rze saa sac sae sag sar sas saz sca scc sce scg scr scs se- sea sec see seg ser ses sez sga sgc sge sgg sgr sgs sr- sra src sre srg srr srs ss- ssa ssc sse ssg ssr sss ssz sza sze szr z-g zaa zac zag zar zas zaz zce zcs zea zec zee zer zes zez zgg zgs zrs zsa zse zsg zsz zzr zzs zzz