-er ddd dde ddi ddo ddr dds ddx de- ded dee dei deo der des dex di- did die dii dio dir dis dix dod doe doi doo dor dos dox drd dre dri dro drr drs drx dsd dse dsi dso dsr dss dsx dxd dxi dxo dxr dxs dxx ed- edd ede edi edo edr eds edx eed eee eeo eer ees eex eid eie eii eio eir eis eix eo- eod eoe eoi eoo eor eos erd ere eri ero err ers es- esd ese esi eso esr ess esx ex- exd exe exi exo exr exs exx i-d idd ide idi ido idr ids idx ie- ied iee iei ier ies iex iid iie iii iio iir iis iix io- iod ioe ioi ioo ior ios ir- ird ire iri iro irr irs irx is- isd ise isi iso isr iss ixe ixi o-i odd ode odi odo odr ods oed oee oei oeo oer oes oex oid oie oii oio oir ois oo- ood ooi ooo oor oos oox or- ord ore ori oro orr ors orx os- osd ose osi oso osr oss osx ox- oxi oxo oxx rdd rde rdi rdo rdr rds rdx re- red ree rei reo rer res rex rid rie rii rio rir ris rix rod roe roi roo ror ros rox rrd rri rrr rrs rsd rse rsi rso rsr rss rsx rxr rxs sdd sde sdi sdo sdr sds se- sed see sei seo ser ses sex sid sie sii sio sir sis six sod soe soi soo sor sos sox sr- srd sre sri sro srr srs srx ss- ssd sse ssi sso ssr sss ssx sxi sxs xde xdi xdr xds xed xee xer xes xex xie xii xio xis xix xod xoi xoo xor xos xox xrd xrx xsi xss xxi xxo xxx