-er ddd dde ddo ddp ddr dds ddx de- ded dee deo dep der des dex dod doe doo dop dor dos dox dpd dpe dpo dpp dpr dps drd dre dro drp drr drs drx dsd dse dso dsp dsr dss dsx dxd dxo dxp dxr dxs dxx ed- edd ede edo edp edr eds edx eed eee eeo eep eer ees eex eo- eod eoe eoo eop eor eos ep- epd epe epo epp epr eps epx erd ere ero erp err ers es- esd ese eso esp esr ess esx ex- exd exe exo exp exr exs exx odd ode odo odp odr ods oed oee oeo oep oer oes oex oo- ood ooo oop oor oos oox op- opd ope opo opp opr ops opx or- ord ore oro orp orr ors orx os- osd ose oso osp osr oss osx ox- oxo oxx p-p pdd pde pdo pdp pdr pds pdx ped pee peo pep per pes pex pod poe poo pop por pos pox ppd ppe ppo ppp ppr pps ppx prd pre pro prp prr prs prx ps- psd pse pso psp psr pss psx pxe pxr pxs rdd rde rdo rdp rdr rds rdx re- red ree reo rep rer res rex rod roe roo rop ror ros rox rpd rpe rpo rpp rpr rps rpx rrd rrp rrr rrs rsd rse rso rsp rsr rss rsx rxp rxr rxs sdd sde sdo sdp sdr sds se- sed see seo sep ser ses sex sod soe soo sop sor sos sox spd spe spo spp spr sps spx sr- srd sre sro srp srr srs srx ss- ssd sse sso ssp ssr sss ssx sxs xde xdr xds xed xee xep xer xes xex xod xoo xop xor xos xox xpd xpe xpo xpp xps xrd xrx xsp xss xxo xxp xxx