-er a-a aaa aad aae aao aap aar aax ad- ada add ade ado adp adr adx aea aed aee aeo aep aer aex aoa aod aoe aoo aop aor aox ap- apa apd ape apo app apr apx ar- ara ard are aro arp arr arx ax- axa axe axo axp axr axx daa dad dae dao dap dar dax dda ddd dde ddo ddp ddr ddx de- dea ded dee deo dep der dex doa dod doe doo dop dor dox dpa dpd dpe dpo dpp dpr dra drd dre dro drp drr drx dxd dxo dxp dxr dxx eaa ead eae eao eap ear eax ed- eda edd ede edo edp edr edx eea eed eee eeo eep eer eex eo- eoa eod eoe eoo eop eor ep- epa epd epe epo epp epr epx era erd ere ero erp err ex- exa exd exe exo exp exr exx oaa oad oae oao oap oar oax oda odd ode odo odp odr oea oed oee oeo oep oer oex oo- ooa ood ooo oop oor oox op- opa opd ope opo opp opr opx or- ora ord ore oro orp orr orx ox- oxa oxo oxx p-p paa pad pae pao pap par pax pda pdd pde pdo pdp pdr pdx pea ped pee peo pep per pex poa pod poe poo pop por pox ppa ppd ppe ppo ppp ppr ppx pra prd pre pro prp prr prx pxe pxr ra- raa rad rae rao rap rar rax rda rdd rde rdo rdp rdr rdx re- rea red ree reo rep rer rex roa rod roe roo rop ror rox rpa rpd rpe rpo rpp rpr rpx rra rrd rrp rrr rxp rxr xaa xad xap xar xda xde xdr xed xee xep xer xex xoa xod xoo xop xor xox xpa xpd xpe xpo xpp xrd xrx xxo xxp xxx