-er c-- ccc ccd cce ccg cco ccp ccr cdc cdd cde cdg cdo cdp cdr ce- cec ced cee ceg ceo cep cer cgc cgd cge cgg cgo cgp cgr co- coc cod coe cog coo cop cor cpc cpd cpe cpg cpo cpp cpr crc crd cre crg cro crp crr dcc dcd dce dcg dco dcp dcr ddc ddd dde ddg ddo ddp ddr de- dec ded dee deg deo dep der dgc dgd dge dgg dgp dgr doc dod doe dog doo dop dor dpc dpd dpe dpg dpo dpp dpr drc drd dre drg dro drp drr ec- ecc ecd ece ecg eco ecr ed- edc edd ede edg edo edp edr eec eed eee eeg eeo eep eer egc egd ege egg ego egp egr eo- eoc eod eoe eog eoo eop eor ep- epc epd epe epg epo epp epr erc erd ere erg ero erp err g-d g-p gcc gcd gce gcg gco gcp gcr gdc gdd gde gdo gdp gdr ge- gec ged gee geg geo gep ger ggc ggd ggg ggo ggp ggr goc god goe gog goo gop gor gpc gpd gpe gpg gpo gpp gpr grc grd gre grg gro grp grr oc- occ ocd ocg oco ocp ocr odc odd ode odg odo odp odr oec oed oee oeg oeo oep oer ogc ogd oge ogg ogo ogp oo- ooc ood oog ooo oop oor op- opc opd ope opg opo opp opr or- orc ord ore org oro orp orr p-p pcc pcd pce pcg pco pcp pcr pdc pdd pde pdg pdo pdp pdr pec ped pee peg peo pep per pgc pgd pge pgg pgo pgp pgr poc pod poe pog poo pop por ppc ppd ppe ppg ppo ppp ppr prc prd pre prg pro prp prr rcc rcd rce rcg rco rcp rcr rdc rdd rde rdg rdo rdp rdr re- rec red ree reg reo rep rer rgc rgd rge rgg rgo rgp rgr roc rod roe rog roo rop ror rpc rpd rpe rpg rpo rpp rpr rrc rrd rrg rrp rrr