-er c-- ccc cce ccn cco ccr ccv ce- cec cee cen ceo cer cev cn- cnc cne cnn cno cnr cnv co- coc coe con coo cor cov crc cre crn cro crr crv cvc cve cvn cvo cvr cvv ec- ecc ece ecn eco ecr ecv eec eee een eeo eer eev en- enc ene enn eno enr env eo- eoc eoe eon eoo eor erc ere ern ero err erv evc eve evn evo evr evv ncc nce ncn nco ncr ncv ne- nec nee nen neo ner nev nnc nne nnn nno nnv no- noc noe non noo nor nov nrc nre nrn nro nrr nrv nvc nve nvn nvv oc- occ ocn oco ocr ocv oec oee oen oeo oer on- onc one onn ono onr oo- ooc oon ooo oor oov or- orc ore orn oro orr orv ov- ovc ove ovo ovv rcc rce rcn rco rcr rcv re- rec ree ren reo rer rev rnc rnn rno rnr rnv roc roe ron roo ror rov rrc rrn rrr rvc rve rvn rvo rvr rvv v-e vcc vce vcn vco vcr vec vee ven veo ver vn- vno vnr vnv voc voe von voo vor vov vrc vre vrn vrr vvc vvo vvr vvv