-er c-- ccc cce cck ccn cco ccr ccv ce- cec cee cek cen ceo cer cev ckc cko cn- cnc cne cnn cno cnr cnv co- coc coe cok con coo cor cov crc cre crk crn cro crr crv cvc cve cvk cvn cvo cvr cvv ec- ecc ece eck ecn eco ecr ecv eec eee eek een eeo eer eev ekc eke eko ekr ekv en- enc ene enk enn eno enr env eo- eoc eoe eok eon eoo eor erc ere erk ern ero err erv evc eve evn evo evr evv kcc kce kck kcn kcr ke- kec kee kek ken keo ker kev kkc kke kkk kkn kkr kkv kn- knc kne knk knn kno knr koc koe kok kon koo kor krc krk krn kro krr krv kvk kvn kvo kvr kvv ncc nce nck ncn nco ncr ncv ne- nec nee nek nen neo ner nev nkc nke nkk nkn nko nkr nnc nne nnk nnn nno nnv no- noc noe nok non noo nor nov nrc nre nrk nrn nro nrr nrv nvc nve nvk nvn nvv oc- occ ock ocn oco ocr ocv oec oee oen oeo oer okc oke okk oko okr on- onc one onk onn ono onr oo- ooc ook oon ooo oor oov or- orc ore ork orn oro orr orv ov- ovc ove ovo ovv rcc rce rcn rco rcr rcv re- rec ree rek ren reo rer rev rkc rke rkk rko rkv rnc rnn rno rnr rnv roc roe rok ron roo ror rov rrc rrk rrn rrr rvc rve rvn rvo rvr rvv v-e vcc vce vcn vco vcr vec vee vek ven veo ver vn- vno vnr vnv voc voe vok von voo vor vov vrc vre vrk vrn vrr vvc vvo vvr vvv