-er a-a a-c a-z aaa aac aae aag aan aar aaz ac- aca acc ace acg acn acr acz aea aec aee aeg aen aer aez ag- aga agc age agg agn agr agz an- ana anc ane ang ann anr anz ar- ara arc are arg arn arr arz az- aza aze azg azn azz c-- caa cac cae cag can car caz cca ccc cce ccg ccn ccr ccz ce- cea cec cee ceg cen cer cez cga cgc cge cgg cgn cgr cn- cna cnc cne cng cnn cnr cra crc cre crg crn crr crz cz- czc cze eaa eac eae eag ean ear eaz ec- eca ecc ece ecg ecn ecr eea eec eee eeg een eer ega egc ege egg egn egr en- ena enc ene eng enn enr enz era erc ere erg ern err erz eze ezr ezz gaa gac gae gag gan gar gaz gca gcc gce gcg gcn gcr ge- gea gec gee geg gen ger gez gga ggc ggg ggn ggr ggz gna gnc gne gnn gnr gra grc gre grg grn grr gza gzr naa nac nae nag nan nar naz nca ncc nce ncg ncn ncr ne- nea nec nee neg nen ner nez nga ngc nge ngg ngn nna nnc nne nng nnn nnz nra nrc nre nrg nrn nrr nrz nze nzg nzz ra- raa rac rae rag ran rar raz rca rcc rce rcg rcn rcr re- rea rec ree reg ren rer rez rga rgc rge rgg rgn rgr rna rnc rng rnn rnr rnz rra rrc rrg rrn rrr rza rze z-g zaa zac zag zan zar zaz zce zea zec zee zen zer zez zgg znc zne znn zzr zzz