-er c-- ccc ccd cce ccg cco ccr cdc cdd cde cdg cdo cdr ce- cec ced cee ceg ceo cer cgc cgd cge cgg cgo cgr co- coc cod coe cog coo cor crc crd cre crg cro crr dcc dcd dce dcg dco dcr ddc ddd dde ddg ddo ddr de- dec ded dee deg deo der dgc dgd dge dgg dgr doc dod doe dog doo dor drc drd dre drg dro drr ec- ecc ecd ece ecg eco ecr ed- edc edd ede edg edo edr eec eed eee eeg eeo eer egc egd ege egg ego egr eo- eoc eod eoe eog eoo eor erc erd ere erg ero err g-d gcc gcd gce gcg gco gcr gdc gdd gde gdo gdr ge- gec ged gee geg geo ger ggc ggd ggg ggo ggr goc god goe gog goo gor grc grd gre grg gro grr oc- occ ocd ocg oco ocr odc odd ode odg odo odr oec oed oee oeg oeo oer ogc ogd oge ogg ogo oo- ooc ood oog ooo oor or- orc ord ore org oro orr rcc rcd rce rcg rco rcr rdc rdd rde rdg rdo rdr re- rec red ree reg reo rer rgc rgd rge rgg rgo rgr roc rod roe rog roo ror rrc rrd rrg rrr