-er c-- ccc cce ccg cco ccr ce- cec cee ceg ceo cer cgc cge cgg cgo cgr co- coc coe cog coo cor crc cre crg cro crr ec- ecc ece ecg eco ecr eec eee eeg eeo eer egc ege egg ego egr eo- eoc eoe eog eoo eor erc ere erg ero err gcc gce gcg gco gcr ge- gec gee geg geo ger ggc ggg ggo ggr goc goe gog goo gor grc gre grg gro grr oc- occ ocg oco ocr oec oee oeg oeo oer ogc oge ogg ogo oo- ooc oog ooo oor or- orc ore org oro orr rcc rce rcg rco rcr re- rec ree reg reo rer rgc rge rgg rgo rgr roc roe rog roo ror rrc rrg rrr