-er a-a a-c aaa aac aad aae aag aao aar ac- aca acc acd ace acg aco acr ad- ada adc add ade adg ado adr aea aec aed aee aeg aeo aer ag- aga agc agd age agg ago agr aoa aoc aod aoe aog aoo aor ar- ara arc ard are arg aro arr c-- caa cac cad cae cag cao car cca ccc ccd cce ccg cco ccr cda cdc cdd cde cdg cdo cdr ce- cea cec ced cee ceg ceo cer cga cgc cgd cge cgg cgo cgr co- coa coc cod coe cog coo cor cra crc crd cre crg cro crr daa dac dad dae dag dao dar dca dcc dcd dce dcg dco dcr dda ddc ddd dde ddg ddo ddr de- dea dec ded dee deg deo der dga dgc dgd dge dgg dgr doa doc dod doe dog doo dor dra drc drd dre drg dro drr eaa eac ead eae eag eao ear ec- eca ecc ecd ece ecg eco ecr ed- eda edc edd ede edg edo edr eea eec eed eee eeg eeo eer ega egc egd ege egg ego egr eo- eoa eoc eod eoe eog eoo eor era erc erd ere erg ero err g-d gaa gac gad gae gag gao gar gca gcc gcd gce gcg gco gcr gda gdc gdd gde gdo gdr ge- gea gec ged gee geg geo ger gga ggc ggd ggg ggo ggr goa goc god goe gog goo gor gra grc grd gre grg gro grr oaa oac oad oae oag oao oar oc- oca occ ocd ocg oco ocr oda odc odd ode odg odo odr oea oec oed oee oeg oeo oer oga ogc ogd oge ogg ogo oo- ooa ooc ood oog ooo oor or- ora orc ord ore org oro orr ra- raa rac rad rae rag rao rar rca rcc rcd rce rcg rco rcr rda rdc rdd rde rdg rdo rdr re- rea rec red ree reg reo rer rga rgc rgd rge rgg rgo rgr roa roc rod roe rog roo ror rra rrc rrd rrg rrr