-er a-a a-b a-t aaa aab aad aae aao aar aas aat aax ab- aba abb abd abe abo abr abs abt abx ad- ada adb add ade ado adr ads adt adx aea aeb aed aee aeo aer aes aet aex aoa aob aod aoe aoo aor aos aot aox ar- ara arb ard are aro arr ars art arx as- asa asb asd ase aso asr ass ast asx at- ata atb atd ate ato atr ats att atx ax- axa axe axo axr axs axt axx baa bab bad bae bao bar bas bat bax bba bbb bbd bbe bbo bbr bbs bbt bbx bda bdb bdd bde bdo bdr bds bdt bdx be- bea beb bed bee beo ber bes bet bex boa bob bod boe boo bor bos bot box bra brb brd bre bro brr brs brt brx bsa bsb bsd bse bso bsr bss bst bsx bta btb btd bte bto btr bts btt btx bxb bxd bxo bxx daa dab dad dae dao dar das dat dax dba dbb dbd dbe dbo dbr dbs dbt dbx dda ddb ddd dde ddo ddr dds ddt ddx de- dea deb ded dee deo der des det dex doa dob dod doe doo dor dos dot dox dra drb drd dre dro drr drs drt drx dsa dsb dsd dse dso dsr dss dst dsx dta dtb dtd dte dto dtr dts dtt dtx dxd dxo dxr dxs dxt dxx eaa eab ead eae eao ear eas eat eax eba ebb ebd ebe ebo ebr ebs ebt ebx ed- eda edb edd ede edo edr eds edt edx eea eeb eed eee eeo eer ees eet eex eo- eoa eob eod eoe eoo eor eos eot era erb erd ere ero err ers ert es- esa esb esd ese eso esr ess est esx eta etb etd ete eto etr ets ett etx ex- exa exd exe exo exr exs ext exx oaa oab oad oae oao oar oas oat oax ob- oba obb obd obe obo obr obs obt obx oda odb odd ode odo odr ods odt oea oeb oed oee oeo oer oes oet oex oo- ooa oob ood ooo oor oos oot oox or- ora orb ord ore oro orr ors ort orx os- osa osb osd ose oso osr oss ost osx ot- ota otb otd ote oto otr ots ott ox- oxa oxb oxo oxt oxx ra- raa rab rad rae rao rar ras rat rax rba rbb rbd rbe rbo rbr rbs rbt rbx rda rdb rdd rde rdo rdr rds rdt rdx re- rea reb red ree reo rer res ret rex roa rob rod roe roo ror ros rot rox rra rrb rrd rrr rrs rrt rsa rsb rsd rse rso rsr rss rst rsx rta rtb rtd rte rto rtr rts rtt rtx rxr rxs saa sab sad sae sao sar sas sat sax sba sbb sbd sbe sbo sbr sbs sbt sbx sda sdb sdd sde sdo sdr sds sdt se- sea seb sed see seo ser ses set sex soa sob sod soe soo sor sos sot sox sr- sra srb srd sre sro srr srs srt srx ss- ssa ssb ssd sse sso ssr sss sst ssx sta stb std ste sto str sts stt stx sxs sxt t-x taa tab tad tae tao tar tas tat tax tba tbb tbd tbe tbo tbr tbs tbt tda tdb tdd tde tdo tdr tds tdt tdx te- tea teb ted tee teo ter tes tet tex to- toa tob tod toe too tor tos tot tox tra trb trd tre tro trr trs trt trx tsa tsb tsd tse tso tsr tss tst tsx tta ttb ttd tte tto ttr tts ttt ttx txe txs txt xaa xad xar xas xat xbe xbr xbx xda xdb xde xdr xds xdt xed xee xer xes xet xex xoa xod xoo xor xos xot xox xrd xrt xrx xsa xsb xss xst xtr xts xtx xxo xxx