-er ddd dde ddi ddr dds ddx de- ded dee dei der des dev dex di- did die dii dir dis div dix drd dre dri drr drs drv drx dsd dse dsi dsr dss dsv dsx dvd dve dvi dvr dvs dvx dxd dxi dxr dxs dxx ed- edd ede edi edr eds edx eed eee eer ees eev eex eid eie eii eir eis eiv eix erd ere eri err ers erv es- esd ese esi esr ess esv esx evd eve evi evr evs evv ex- exd exe exi exr exs exx i-d i-v idd ide idi idr ids idv idx ie- ied iee iei ier ies iev iex iid iie iii iir iis iix ir- ird ire iri irr irs irv irx is- isd ise isi isr iss isv ivd ive ivi ivr ivs ivv ivx ixe ixi rdd rde rdi rdr rds rdv rdx re- red ree rei rer res rev rex rid rie rii rir ris riv rix rrd rri rrr rrs rsd rse rsi rsr rss rsv rsx rvd rve rvi rvr rvs rvv rxr rxs sdd sde sdi sdr sds sdv se- sed see sei ser ses sev sex sid sie sii sir sis siv six sr- srd sre sri srr srs srv srx ss- ssd sse ssi ssr sss ssv ssx svd sve svi svr svs svv svx sxi sxs v-e vdd vde vdi vdr vds vdv vdx ved vee vei ver ves vex vi- vid vie vii vir vis viv vix vrd vre vri vrr vrs vsd vse vsi vsr vss vsv vvi vvr vvs vvv vxd vxr vxs vxv xde xdi xdr xds xdv xed xee xer xes xev xex xie xii xis xiv xix xrd xrx xsi xss xvi xxi xxv xxx