-er ddd dde ddn ddo ddp ddr ddx de- ded dee den deo dep der dex dnd dne dnn dno dnp dnr dod doe don doo dop dor dox dpd dpe dpn dpo dpp dpr drd dre drn dro drp drr drx dxd dxn dxo dxp dxr dxx ed- edd ede edn edo edp edr edx eed eee een eeo eep eer eex en- end ene enn eno enp enr eo- eod eoe eon eoo eop eor ep- epd epe epn epo epp epr epx erd ere ern ero erp err ex- exd exe exo exp exr exx ndd nde ndn ndo ndp ndr ne- ned nee nen neo nep ner nex nne nnn nno nnp no- nod noe non noo nop nor nox npd npe npn npo npp npr nrd nre nrn nro nrp nrr nrx nxd odd ode odn odo odp odr oed oee oen oeo oep oer oex on- ond one onn ono onp onr onx oo- ood oon ooo oop oor oox op- opd ope opn opo opp opr opx or- ord ore orn oro orp orr orx ox- oxn oxo oxx p-p pdd pde pdn pdo pdp pdr pdx ped pee pen peo pep per pex pn- pnd pne pnn pno pnp pnr pnx pod poe pon poo pop por pox ppd ppe ppn ppo ppp ppr ppx prd pre prn pro prp prr prx pxe pxr rdd rde rdn rdo rdp rdr rdx re- red ree ren reo rep rer rex rnd rnn rno rnp rnr rod roe ron roo rop ror rox rpd rpe rpn rpo rpp rpr rpx rrd rrn rrp rrr rxp rxr xde xdr xed xee xen xep xer xex xno xod xon xoo xop xor xox xpd xpe xpn xpo xpp xrd xrx xxo xxp xxx