-er a-a a-c aaa aac aad aae aag aar ac- aca acc acd ace acg acr ad- ada adc add ade adg adr aea aec aed aee aeg aer ag- aga agc agd age agg agr ar- ara arc ard are arg arr c-- caa cac cad cae cag car cca ccc ccd cce ccg ccr cda cdc cdd cde cdg cdr ce- cea cec ced cee ceg cer cga cgc cgd cge cgg cgr cra crc crd cre crg crr daa dac dad dae dag dar dca dcc dcd dce dcg dcr dda ddc ddd dde ddg ddr de- dea dec ded dee deg der dga dgc dgd dge dgg dgr dra drc drd dre drg drr eaa eac ead eae eag ear ec- eca ecc ecd ece ecg ecr ed- eda edc edd ede edg edr eea eec eed eee eeg eer ega egc egd ege egg egr era erc erd ere erg err g-d gaa gac gad gae gag gar gca gcc gcd gce gcg gcr gda gdc gdd gde gdr ge- gea gec ged gee geg ger gga ggc ggd ggg ggr gra grc grd gre grg grr ra- raa rac rad rae rag rar rca rcc rcd rce rcg rcr rda rdc rdd rde rdg rdr re- rea rec red ree reg rer rga rgc rgd rge rgg rgr rra rrc rrd rrg rrr