-er c-- ccc cce ccg cck ccn cco ccr ce- cec cee ceg cek cen ceo cer cgc cge cgg cgn cgo cgr ckc cko cn- cnc cne cng cnn cno cnr co- coc coe cog cok con coo cor crc cre crg crk crn cro crr ec- ecc ece ecg eck ecn eco ecr eec eee eeg eek een eeo eer egc ege egg egn ego egr ekc eke ekg eko ekr en- enc ene eng enk enn eno enr eo- eoc eoe eog eok eon eoo eor erc ere erg erk ern ero err gcc gce gcg gck gcn gco gcr ge- gec gee geg gek gen geo ger ggc ggg ggn ggo ggr gkn gko gnc gne gnn gno gnr goc goe gog gok gon goo gor grc gre grg grk grn gro grr kcc kce kcg kck kcn kcr ke- kec kee keg kek ken keo ker kgc kgo kkc kke kkk kkn kkr kn- knc kne kng knk knn kno knr koc koe kog kok kon koo kor krc krg krk krn kro krr ncc nce ncg nck ncn nco ncr ne- nec nee neg nek nen neo ner ngc nge ngg ngk ngn ngo nkc nke nkk nkn nko nkr nnc nne nng nnk nnn nno no- noc noe nog nok non noo nor nrc nre nrg nrk nrn nro nrr oc- occ ocg ock ocn oco ocr oec oee oeg oen oeo oer ogc oge ogg ogn ogo okc oke okg okk oko okr on- onc one ong onk onn ono onr oo- ooc oog ook oon ooo oor or- orc ore org ork orn oro orr rcc rce rcg rcn rco rcr re- rec ree reg rek ren reo rer rgc rge rgg rgk rgn rgo rgr rkc rke rkg rkk rko rnc rng rnn rno rnr roc roe rog rok ron roo ror rrc rrg rrk rrn rrr