-er c-- ccc cce ccn cco ccr ce- cec cee cen ceo cer cn- cnc cne cnn cno cnr co- coc coe con coo cor crc cre crn cro crr ec- ecc ece ecn eco ecr eec eee een eeo eer en- enc ene enn eno enr eo- eoc eoe eon eoo eor erc ere ern ero err ncc nce ncn nco ncr ne- nec nee nen neo ner nnc nne nnn nno no- noc noe non noo nor nrc nre nrn nro nrr oc- occ ocn oco ocr oec oee oen oeo oer on- onc one onn ono onr oo- ooc oon ooo oor or- orc ore orn oro orr rcc rce rcn rco rcr re- rec ree ren reo rer rnc rnn rno rnr roc roe ron roo ror rrc rrn rrr