-er ddd dde ddk ddo ddp ddr dds de- ded dee dek deo dep der des dke dkk dko dkp dkr dks dod doe dok doo dop dor dos dpd dpe dpk dpo dpp dpr dps drd dre drk dro drp drr drs dsd dse dsk dso dsp dsr dss ed- edd ede edk edo edp edr eds eed eee eek eeo eep eer ees ekd eke eko ekp ekr eks eo- eod eoe eok eoo eop eor eos ep- epd epe epo epp epr eps erd ere erk ero erp err ers es- esd ese esk eso esp esr ess kde kdk kdo kdp kdr kds ke- ked kee kek keo kep ker kes kke kkk kkp kkr kks kod koe kok koo kop kor kos kpd kpe kpk kpo kpp kpr kps krd krk kro krp krr krs ksd kse ksk kso ksp ksr kss odd ode odo odp odr ods oed oee oeo oep oer oes okd oke okk oko okp okr oks oo- ood ook ooo oop oor oos op- opd ope opk opo opp opr ops or- ord ore ork oro orp orr ors os- osd ose osk oso osp osr oss p-p pdd pde pdk pdo pdp pdr pds ped pee pek peo pep per pes pkd pke pko pkp pkr pks pod poe pok poo pop por pos ppd ppe ppk ppo ppp ppr pps prd pre prk pro prp prr prs ps- psd pse psk pso psp psr pss rdd rde rdo rdp rdr rds re- red ree rek reo rep rer res rke rkk rko rkp rks rod roe rok roo rop ror ros rpd rpe rpk rpo rpp rpr rps rrd rrk rrp rrr rrs rsd rse rsk rso rsp rsr rss sdd sde sdk sdo sdp sdr sds se- sed see sek seo sep ser ses sk- skd ske skk sko skp skr sks sod soe sok soo sop sor sos spd spe spk spo spp spr sps sr- srd sre srk sro srp srr srs ss- ssd sse ssk sso ssp ssr sss