-er c-- ccc cce cco ccp ccr ccv ce- cec cee ceo cep cer cev co- coc coe coo cop cor cov cpc cpe cpo cpp cpr cpv crc cre cro crp crr crv cvc cve cvo cvp cvr cvv ec- ecc ece eco ecr ecv eec eee eeo eep eer eev eo- eoc eoe eoo eop eor ep- epc epe epo epp epr erc ere ero erp err erv evc eve evo evp evr evv oc- occ oco ocp ocr ocv oec oee oeo oep oer oo- ooc ooo oop oor oov op- opc ope opo opp opr opv or- orc ore oro orp orr orv ov- ovc ove ovo ovp ovv p-p pcc pce pco pcp pcr pcv pec pee peo pep per pev poc poe poo pop por pov ppc ppe ppo ppp ppr ppv prc pre pro prp prr prv pvc pve pvo pvp pvr pvv rcc rce rco rcp rcr rcv re- rec ree reo rep rer rev roc roe roo rop ror rov rpc rpe rpo rpp rpr rpv rrc rrp rrr rvc rve rvo rvp rvr rvv v-e vcc vce vco vcp vcr vec vee veo vep ver voc voe voo vop vor vov vpc vpe vpo vpp vpr vrc vre vrp vrr vvc vvo vvr vvv