-er ddd dde ddg ddo ddp ddr de- ded dee deg deo dep der dgd dge dgg dgp dgr dod doe dog doo dop dor dpd dpe dpg dpo dpp dpr drd dre drg dro drp drr ed- edd ede edg edo edp edr eed eee eeg eeo eep eer egd ege egg ego egp egr eo- eod eoe eog eoo eop eor ep- epd epe epg epo epp epr erd ere erg ero erp err g-d g-p gdd gde gdo gdp gdr ge- ged gee geg geo gep ger ggd ggg ggo ggp ggr god goe gog goo gop gor gpd gpe gpg gpo gpp gpr grd gre grg gro grp grr odd ode odg odo odp odr oed oee oeg oeo oep oer ogd oge ogg ogo ogp oo- ood oog ooo oop oor op- opd ope opg opo opp opr or- ord ore org oro orp orr p-p pdd pde pdg pdo pdp pdr ped pee peg peo pep per pgd pge pgg pgo pgp pgr pod poe pog poo pop por ppd ppe ppg ppo ppp ppr prd pre prg pro prp prr rdd rde rdg rdo rdp rdr re- red ree reg reo rep rer rgd rge rgg rgo rgp rgr rod roe rog roo rop ror rpd rpe rpg rpo rpp rpr rrd rrg rrp rrr