-er ddd dde ddo ddp ddr ddt ddx de- ded dee deo dep der det dex dod doe doo dop dor dot dox dpd dpe dpo dpp dpr dpt drd dre dro drp drr drt drx dtd dte dto dtp dtr dtt dtx dxd dxo dxp dxr dxt dxx ed- edd ede edo edp edr edt edx eed eee eeo eep eer eet eex eo- eod eoe eoo eop eor eot ep- epd epe epo epp epr ept epx erd ere ero erp err ert etd ete eto etp etr ett etx ex- exd exe exo exp exr ext exx odd ode odo odp odr odt oed oee oeo oep oer oet oex oo- ood ooo oop oor oot oox op- opd ope opo opp opr opt opx or- ord ore oro orp orr ort orx ot- otd ote oto otp otr ott ox- oxo oxt oxx p-p pdd pde pdo pdp pdr pdt pdx ped pee peo pep per pet pex pod poe poo pop por pot pox ppd ppe ppo ppp ppr ppt ppx prd pre pro prp prr prt prx pt- ptd pte pto ptp ptr ptt ptx pxe pxr pxt rdd rde rdo rdp rdr rdt rdx re- red ree reo rep rer ret rex rod roe roo rop ror rot rox rpd rpe rpo rpp rpr rpt rpx rrd rrp rrr rrt rtd rte rto rtp rtr rtt rtx rxp rxr t-x tdd tde tdo tdp tdr tdt tdx te- ted tee teo tep ter tet tex to- tod toe too top tor tot tox tpd tpe tpo tpp tpr tpt tpx trd tre tro trp trr trt trx ttd tte tto ttp ttr ttt ttx txe txt xde xdr xdt xed xee xep xer xet xex xod xoo xop xor xot xox xpd xpe xpo xpp xpt xrd xrt xrx xtp xtr xtx xxo xxp xxx