-er c-- ccc cce cco ccp ccr ce- cec cee ceo cep ceq cer co- coc coe coo cop coq cor cpc cpe cpo cpp cpq cpr cqc cqo crc cre cro crp crq crr ec- ecc ece eco ecq ecr eec eee eeo eep eer eo- eoc eoe eoo eop eoq eor ep- epc epe epo epp epq epr eqe eqp eqq erc ere ero erp erq err oc- occ oco ocp ocr oec oee oeo oep oer oo- ooc ooo oop oor op- opc ope opo opp opq opr oqo or- orc ore oro orp orr p-p pcc pce pco pcp pcq pcr pec pee peo pep per poc poe poo pop por ppc ppe ppo ppp ppq ppr pqq pqr prc pre pro prp prq prr qcc qco qcp qec qee qeo qep qoo qop qor qpc qpp qpr qqq qrc qre qrp rcc rce rco rcp rcr re- rec ree reo rep req rer roc roe roo rop ror rpc rpe rpo rpp rpr rqc rrc rrp rrq rrr