a-a a-b a-i aaa aab aad aai aao aas ab- aba abb abd abi abo abs ad- ada adb add adi ado ads ai- aia aib aid aii aio ais aoa aob aod aoi aoo aos as- asa asb asd asi aso ass baa bab bad bai bao bas bba bbb bbd bbi bbo bbs bda bdb bdd bdi bdo bds bi- bia bib bid bii bio bis boa bob bod boi boo bos bsa bsb bsd bsi bso bss daa dab dad dai dao das dba dbb dbd dbi dbo dbs dda ddb ddd ddi ddo dds di- dia dib did dii dio dis doa dob dod doi doo dos dsa dsb dsd dsi dso dss i-d ia- iaa iab iad iai iao ias iba ibb ibd ibi ibo ibs ida idb idd idi ido ids iia iib iid iii iio iis io- ioa iob iod ioi ioo ios is- isa isb isd isi iso iss o-i oaa oab oad oai oao oas ob- oba obb obd obi obo obs oda odb odd odi odo ods oia oib oid oii oio ois oo- ooa oob ood ooi ooo oos os- osa osb osd osi oso oss saa sab sad sai sao sas sba sbb sbd sbi sbo sbs sda sdb sdd sdi sdo sds sia sib sid sii sio sis soa sob sod soi soo sos ss- ssa ssb ssd ssi sso sss