a-a a-b a-i aaa aab aad aai aao aar aas ab- aba abb abd abi abo abr abs ad- ada adb add adi ado adr ads ai- aia aib aid aii aio air ais aoa aob aod aoi aoo aor aos ar- ara arb ard ari aro arr ars as- asa asb asd asi aso asr ass baa bab bad bai bao bar bas bba bbb bbd bbi bbo bbr bbs bda bdb bdd bdi bdo bdr bds bi- bia bib bid bii bio bir bis boa bob bod boi boo bor bos bra brb brd bri bro brr brs bsa bsb bsd bsi bso bsr bss daa dab dad dai dao dar das dba dbb dbd dbi dbo dbr dbs dda ddb ddd ddi ddo ddr dds di- dia dib did dii dio dir dis doa dob dod doi doo dor dos dra drb drd dri dro drr drs dsa dsb dsd dsi dso dsr dss i-d ia- iaa iab iad iai iao iar ias iba ibb ibd ibi ibo ibr ibs ida idb idd idi ido idr ids iia iib iid iii iio iir iis io- ioa iob iod ioi ioo ior ios ir- ira irb ird iri iro irr irs is- isa isb isd isi iso isr iss o-i oaa oab oad oai oao oar oas ob- oba obb obd obi obo obr obs oda odb odd odi odo odr ods oia oib oid oii oio oir ois oo- ooa oob ood ooi ooo oor oos or- ora orb ord ori oro orr ors os- osa osb osd osi oso osr oss ra- raa rab rad rai rao rar ras rba rbb rbd rbi rbo rbr rbs rda rdb rdd rdi rdo rdr rds ria rib rid rii rio rir ris roa rob rod roi roo ror ros rra rrb rrd rri rrr rrs rsa rsb rsd rsi rso rsr rss saa sab sad sai sao sar sas sba sbb sbd sbi sbo sbr sbs sda sdb sdd sdi sdo sdr sds sia sib sid sii sio sir sis soa sob sod soi soo sor sos sr- sra srb srd sri sro srr srs ss- ssa ssb ssd ssi sso ssr sss