-er a-a a-b aaa aab aad aae aao aar aas ab- aba abb abd abe abo abr abs ad- ada adb add ade ado adr ads aea aeb aed aee aeo aer aes aoa aob aod aoe aoo aor aos ar- ara arb ard are aro arr ars as- asa asb asd ase aso asr ass baa bab bad bae bao bar bas bba bbb bbd bbe bbo bbr bbs bda bdb bdd bde bdo bdr bds be- bea beb bed bee beo ber bes boa bob bod boe boo bor bos bra brb brd bre bro brr brs bsa bsb bsd bse bso bsr bss daa dab dad dae dao dar das dba dbb dbd dbe dbo dbr dbs dda ddb ddd dde ddo ddr dds de- dea deb ded dee deo der des doa dob dod doe doo dor dos dra drb drd dre dro drr drs dsa dsb dsd dse dso dsr dss eaa eab ead eae eao ear eas eba ebb ebd ebe ebo ebr ebs ed- eda edb edd ede edo edr eds eea eeb eed eee eeo eer ees eo- eoa eob eod eoe eoo eor eos era erb erd ere ero err ers es- esa esb esd ese eso esr ess oaa oab oad oae oao oar oas ob- oba obb obd obe obo obr obs oda odb odd ode odo odr ods oea oeb oed oee oeo oer oes oo- ooa oob ood ooo oor oos or- ora orb ord ore oro orr ors os- osa osb osd ose oso osr oss ra- raa rab rad rae rao rar ras rba rbb rbd rbe rbo rbr rbs rda rdb rdd rde rdo rdr rds re- rea reb red ree reo rer res roa rob rod roe roo ror ros rra rrb rrd rrr rrs rsa rsb rsd rse rso rsr rss saa sab sad sae sao sar sas sba sbb sbd sbe sbo sbr sbs sda sdb sdd sde sdo sdr sds se- sea seb sed see seo ser ses soa sob sod soe soo sor sos sr- sra srb srd sre sro srr srs ss- ssa ssb ssd sse sso ssr sss