c-- ccc ccd cce cco ccp cdc cdd cde cdo cdp ce- cec ced cee ceo cep co- coc cod coe coo cop cpc cpd cpe cpo cpp dcc dcd dce dco dcp ddc ddd dde ddo ddp de- dec ded dee deo dep doc dod doe doo dop dpc dpd dpe dpo dpp ec- ecc ecd ece eco ed- edc edd ede edo edp eec eed eee eeo eep eo- eoc eod eoe eoo eop ep- epc epd epe epo epp oc- occ ocd oco ocp odc odd ode odo odp oec oed oee oeo oep oo- ooc ood ooo oop op- opc opd ope opo opp p-p pcc pcd pce pco pcp pdc pdd pde pdo pdp pec ped pee peo pep poc pod poe poo pop ppc ppd ppe ppo ppp