a-a a-b aaa aab aad aae aaf aao aas ab- aba abb abd abe abf abo abs ad- ada adb add ade adf ado ads aea aeb aed aee aef aeo aes af- afa afb afd afe aff afo afs aoa aob aod aoe aof aoo aos as- asa asb asd ase asf aso ass baa bab bad bae baf bao bas bba bbb bbd bbe bbf bbo bbs bda bdb bdd bde bdf bdo bds be- bea beb bed bee bef beo bes bfa bfb bfd bfe bff bfo bfs boa bob bod boe bof boo bos bsa bsb bsd bse bsf bso bss daa dab dad dae daf dao das dba dbb dbd dbe dbf dbo dbs dda ddb ddd dde ddf ddo dds de- dea deb ded dee def deo des dfa dfb dfd dfe dff dfo dfs doa dob dod doe dof doo dos dsa dsb dsd dse dsf dso dss eaa eab ead eae eaf eao eas eba ebb ebd ebe ebf ebo ebs ed- eda edb edd ede edf edo eds eea eeb eed eee eef eeo ees ef- efa efb efd efe eff efo efs eo- eoa eob eod eoe eof eoo eos es- esa esb esd ese esf eso ess faa fab fad fae faf fao fas fba fbb fbd fbe fbf fbo fbs fda fdb fdd fde fdf fdo fds fea feb fed fee fef feo fes ffa ffd ffe fff ffo ffs foa fob foe fof foo fos fsa fsb fsd fse fsf fso fss oaa oab oad oae oaf oao oas ob- oba obb obd obe obf obo obs oda odb odd ode odf odo ods oea oeb oed oee oef oeo oes of- ofa ofb ofd ofe off ofo ofs oo- ooa oob ood oof ooo oos os- osa osb osd ose osf oso oss saa sab sad sae saf sao sas sba sbb sbd sbe sbf sbo sbs sda sdb sdd sde sdf sdo sds se- sea seb sed see sef seo ses sfa sfb sfd sfe sff sfo sfs soa sob sod soe sof soo sos ss- ssa ssb ssd sse ssf sso sss