-er c-- ccc ccd cce cco ccp ccr cdc cdd cde cdo cdp cdr ce- cec ced cee ceo cep cer co- coc cod coe coo cop cor cpc cpd cpe cpo cpp cpr crc crd cre cro crp crr dcc dcd dce dco dcp dcr ddc ddd dde ddo ddp ddr de- dec ded dee deo dep der doc dod doe doo dop dor dpc dpd dpe dpo dpp dpr drc drd dre dro drp drr ec- ecc ecd ece eco ecr ed- edc edd ede edo edp edr eec eed eee eeo eep eer eo- eoc eod eoe eoo eop eor ep- epc epd epe epo epp epr erc erd ere ero erp err oc- occ ocd oco ocp ocr odc odd ode odo odp odr oec oed oee oeo oep oer oo- ooc ood ooo oop oor op- opc opd ope opo opp opr or- orc ord ore oro orp orr p-p pcc pcd pce pco pcp pcr pdc pdd pde pdo pdp pdr pec ped pee peo pep per poc pod poe poo pop por ppc ppd ppe ppo ppp ppr prc prd pre pro prp prr rcc rcd rce rco rcp rcr rdc rdd rde rdo rdp rdr re- rec red ree reo rep rer roc rod roe roo rop ror rpc rpd rpe rpo rpp rpr rrc rrd rrp rrr