-er a-a a-b a-t aaa aab aad aae aao aap aar aat aax ab- aba abb abd abe abo abp abr abt abx ad- ada adb add ade ado adp adr adt adx aea aeb aed aee aeo aep aer aet aex aoa aob aod aoe aoo aop aor aot aox ap- apa apb apd ape apo app apr apt apx ar- ara arb ard are aro arp arr art arx at- ata atb atd ate ato atp atr att atx ax- axa axe axo axp axr axt axx b-p baa bab bad bae bao bap bar bat bax bba bbb bbd bbe bbo bbp bbr bbt bbx bda bdb bdd bde bdo bdp bdr bdt bdx be- bea beb bed bee beo bep ber bet bex boa bob bod boe boo bop bor bot box bpa bpb bpd bpe bpo bpp bpr bpt bpx bra brb brd bre bro brp brr brt brx bta btb btd bte bto btp btr btt btx bxb bxd bxo bxx daa dab dad dae dao dap dar dat dax dba dbb dbd dbe dbo dbp dbr dbt dbx dda ddb ddd dde ddo ddp ddr ddt ddx de- dea deb ded dee deo dep der det dex doa dob dod doe doo dop dor dot dox dpa dpb dpd dpe dpo dpp dpr dpt dra drb drd dre dro drp drr drt drx dta dtb dtd dte dto dtp dtr dtt dtx dxd dxo dxp dxr dxt dxx eaa eab ead eae eao eap ear eat eax eba ebb ebd ebe ebo ebp ebr ebt ebx ed- eda edb edd ede edo edp edr edt edx eea eeb eed eee eeo eep eer eet eex eo- eoa eob eod eoe eoo eop eor eot ep- epa epb epd epe epo epp epr ept epx era erb erd ere ero erp err ert eta etb etd ete eto etp etr ett etx ex- exa exd exe exo exp exr ext exx oaa oab oad oae oao oap oar oat oax ob- oba obb obd obe obo obp obr obt obx oda odb odd ode odo odp odr odt oea oeb oed oee oeo oep oer oet oex oo- ooa oob ood ooo oop oor oot oox op- opa opb opd ope opo opp opr opt opx or- ora orb ord ore oro orp orr ort orx ot- ota otb otd ote oto otp otr ott ox- oxa oxb oxo oxt oxx p-p paa pab pad pae pao pap par pat pax pba pbb pbd pbe pbo pbp pbr pbt pbx pda pdb pdd pde pdo pdp pdr pdt pdx pea peb ped pee peo pep per pet pex poa pob pod poe poo pop por pot pox ppa ppb ppd ppe ppo ppp ppr ppt ppx pra prb prd pre pro prp prr prt prx pt- pta ptb ptd pte pto ptp ptr ptt ptx pxe pxr pxt ra- raa rab rad rae rao rap rar rat rax rba rbb rbd rbe rbo rbp rbr rbt rbx rda rdb rdd rde rdo rdp rdr rdt rdx re- rea reb red ree reo rep rer ret rex roa rob rod roe roo rop ror rot rox rpa rpb rpd rpe rpo rpp rpr rpt rpx rra rrb rrd rrp rrr rrt rta rtb rtd rte rto rtp rtr rtt rtx rxp rxr t-x taa tab tad tae tao tap tar tat tax tba tbb tbd tbe tbo tbp tbr tbt tda tdb tdd tde tdo tdp tdr tdt tdx te- tea teb ted tee teo tep ter tet tex to- toa tob tod toe too top tor tot tox tpa tpb tpd tpe tpo tpp tpr tpt tpx tra trb trd tre tro trp trr trt trx tta ttb ttd tte tto ttp ttr ttt ttx txe txt xaa xad xap xar xat xbe xbr xbx xda xdb xde xdr xdt xed xee xep xer xet xex xoa xod xoo xop xor xot xox xpa xpb xpd xpe xpo xpp xpt xrd xrt xrx xtp xtr xtx xxo xxp xxx