-er a-a a-b a-i aaa aab aad aae aai aao aar aas ab- aba abb abd abe abi abo abr abs ad- ada adb add ade adi ado adr ads aea aeb aed aee aei aeo aer aes ai- aia aib aid aie aii aio air ais aoa aob aod aoe aoi aoo aor aos ar- ara arb ard are ari aro arr ars as- asa asb asd ase asi aso asr ass baa bab bad bae bai bao bar bas bba bbb bbd bbe bbi bbo bbr bbs bda bdb bdd bde bdi bdo bdr bds be- bea beb bed bee bei beo ber bes bi- bia bib bid bie bii bio bir bis boa bob bod boe boi boo bor bos bra brb brd bre bri bro brr brs bsa bsb bsd bse bsi bso bsr bss daa dab dad dae dai dao dar das dba dbb dbd dbe dbi dbo dbr dbs dda ddb ddd dde ddi ddo ddr dds de- dea deb ded dee dei deo der des di- dia dib did die dii dio dir dis doa dob dod doe doi doo dor dos dra drb drd dre dri dro drr drs dsa dsb dsd dse dsi dso dsr dss eaa eab ead eae eai eao ear eas eba ebb ebd ebe ebi ebo ebr ebs ed- eda edb edd ede edi edo edr eds eea eeb eed eee eeo eer ees eia eib eid eie eii eio eir eis eo- eoa eob eod eoe eoi eoo eor eos era erb erd ere eri ero err ers es- esa esb esd ese esi eso esr ess i-d ia- iaa iab iad iae iai iao iar ias iba ibb ibd ibe ibi ibo ibr ibs ida idb idd ide idi ido idr ids ie- iea ied iee iei ier ies iia iib iid iie iii iio iir iis io- ioa iob iod ioe ioi ioo ior ios ir- ira irb ird ire iri iro irr irs is- isa isb isd ise isi iso isr iss o-i oaa oab oad oae oai oao oar oas ob- oba obb obd obe obi obo obr obs oda odb odd ode odi odo odr ods oea oeb oed oee oei oeo oer oes oia oib oid oie oii oio oir ois oo- ooa oob ood ooi ooo oor oos or- ora orb ord ore ori oro orr ors os- osa osb osd ose osi oso osr oss ra- raa rab rad rae rai rao rar ras rba rbb rbd rbe rbi rbo rbr rbs rda rdb rdd rde rdi rdo rdr rds re- rea reb red ree rei reo rer res ria rib rid rie rii rio rir ris roa rob rod roe roi roo ror ros rra rrb rrd rri rrr rrs rsa rsb rsd rse rsi rso rsr rss saa sab sad sae sai sao sar sas sba sbb sbd sbe sbi sbo sbr sbs sda sdb sdd sde sdi sdo sdr sds se- sea seb sed see sei seo ser ses sia sib sid sie sii sio sir sis soa sob sod soe soi soo sor sos sr- sra srb srd sre sri sro srr srs ss- ssa ssb ssd sse ssi sso ssr sss