-er ddd dde ddi ddo ddp ddr ddx de- ded dee dei deo dep der dex di- did die dii dio dip dir dix dod doe doi doo dop dor dox dpd dpe dpi dpo dpp dpr drd dre dri dro drp drr drx dxd dxi dxo dxp dxr dxx ed- edd ede edi edo edp edr edx eed eee eeo eep eer eex eid eie eii eio eip eir eix eo- eod eoe eoi eoo eop eor ep- epd epe epi epo epp epr epx erd ere eri ero erp err ex- exd exe exi exo exp exr exx i-d idd ide idi ido idp idr idx ie- ied iee iei iep ier iex iid iie iii iio iip iir iix io- iod ioe ioi ioo iop ior ipd ipe ipi ipo ipp ipr ipx ir- ird ire iri iro irp irr irx ixe ixi o-i odd ode odi odo odp odr oed oee oei oeo oep oer oex oid oie oii oio oip oir oo- ood ooi ooo oop oor oox op- opd ope opi opo opp opr opx or- ord ore ori oro orp orr orx ox- oxi oxo oxx p-p pdd pde pdi pdo pdp pdr pdx ped pee pei peo pep per pex pid pie pii pio pip pir pix pod poe poi poo pop por pox ppd ppe ppi ppo ppp ppr ppx prd pre pri pro prp prr prx pxe pxr rdd rde rdi rdo rdp rdr rdx re- red ree rei reo rep rer rex rid rie rii rio rip rir rix rod roe roi roo rop ror rox rpd rpe rpi rpo rpp rpr rpx rrd rri rrp rrr rxp rxr xde xdi xdr xed xee xep xer xex xie xii xio xix xod xoi xoo xop xor xox xpd xpe xpo xpp xrd xrx xxi xxo xxp xxx