-er c-- ccc cce ccn cco ccp ccr ce- cec cee cen ceo cep cer cn- cnc cne cnn cno cnp cnr co- coc coe con coo cop cor cpc cpe cpn cpo cpp cpr crc cre crn cro crp crr ec- ecc ece ecn eco ecr eec eee een eeo eep eer en- enc ene enn eno enp enr eo- eoc eoe eon eoo eop eor ep- epc epe epn epo epp epr erc ere ern ero erp err ncc nce ncn nco ncp ncr ne- nec nee nen neo nep ner nnc nne nnn nno nnp no- noc noe non noo nop nor npc npe npn npo npp npr nrc nre nrn nro nrp nrr oc- occ ocn oco ocp ocr oec oee oen oeo oep oer on- onc one onn ono onp onr oo- ooc oon ooo oop oor op- opc ope opn opo opp opr or- orc ore orn oro orp orr p-p pcc pce pcn pco pcp pcr pec pee pen peo pep per pn- pnc pne pnn pno pnp pnr poc poe pon poo pop por ppc ppe ppn ppo ppp ppr prc pre prn pro prp prr rcc rce rcn rco rcp rcr re- rec ree ren reo rep rer rnc rnn rno rnp rnr roc roe ron roo rop ror rpc rpe rpn rpo rpp rpr rrc rrn rrp rrr