-er ddd dde ddo ddr dds ddt ddu ddx de- ded dee deo der des det deu dex dod doe doo dor dos dot dou dox drd dre dro drr drs drt dru drx dsd dse dso dsr dss dst dsu dsx dtd dte dto dtr dts dtt dtu dtx dud due duo dur dus dut dux dxd dxo dxr dxs dxt dxx ed- edd ede edo edr eds edt edu edx eed eee eeo eer ees eet eex eo- eod eoe eoo eor eos eot eou erd ere ero err ers ert eru es- esd ese eso esr ess est esu esx etd ete eto etr ets ett etu etx eu- eud eue eur eus eut eux ex- exd exe exo exr exs ext exu exx odd ode odo odr ods odt odu oed oee oeo oer oes oet oex oo- ood ooo oor oos oot oox or- ord ore oro orr ors ort oru orx os- osd ose oso osr oss ost osu osx ot- otd ote oto otr ots ott otu ou- oud oue ouo our ous out ox- oxo oxt oxx rdd rde rdo rdr rds rdt rdu rdx re- red ree reo rer res ret reu rex rod roe roo ror ros rot rou rox rrd rrr rrs rrt rru rsd rse rso rsr rss rst rsu rsx rtd rte rto rtr rts rtt rtu rtx rud rue ruo rur rus rut ruu rux rxr rxs sdd sde sdo sdr sds sdt sdu se- sed see seo ser ses set seu sex sod soe soo sor sos sot sou sox sr- srd sre sro srr srs srt srx ss- ssd sse sso ssr sss sst ssu ssx std ste sto str sts stt stu stx sud sue suo sur sus sut suu sux sxs sxt sxu t-x tdd tde tdo tdr tds tdt tdu tdx te- ted tee teo ter tes tet teu tex to- tod toe too tor tos tot tou tox trd tre tro trr trs trt tru trx tsd tse tso tsr tss tst tsu tsx ttd tte tto ttr tts ttt ttu ttx tud tue tuo tur tus tut tuu tux txe txs txt txu udd ude udo udr uds udt udu udx ued uee uer ues uet uod uoe uoo uor uos uot uox ur- urd ure uro urr urs urt uru urx usd use uso usr uss ust usu usx utd ute uto utr uts utt utu utx uue uur uus uut uuu uxo uxr uxt uxu xde xdr xds xdt xed xee xer xes xet xeu xex xod xoo xor xos xot xox xrd xrt xrx xss xst xtr xts xtx xue xus xxo xxx