a-a a-b a-i aaa aab aad aae aaf aai aao aas ab- aba abb abd abe abf abi abo abs ad- ada adb add ade adf adi ado ads aea aeb aed aee aef aei aeo aes af- afa afb afd afe aff afi afo afs ai- aia aib aid aie aif aii aio ais aoa aob aod aoe aof aoi aoo aos as- asa asb asd ase asf asi aso ass baa bab bad bae baf bai bao bas bba bbb bbd bbe bbf bbi bbo bbs bda bdb bdd bde bdf bdi bdo bds be- bea beb bed bee bef bei beo bes bfa bfb bfd bfe bff bfi bfo bfs bi- bia bib bid bie bif bii bio bis boa bob bod boe bof boi boo bos bsa bsb bsd bse bsf bsi bso bss daa dab dad dae daf dai dao das dba dbb dbd dbe dbf dbi dbo dbs dda ddb ddd dde ddf ddi ddo dds de- dea deb ded dee def dei deo des dfa dfb dfd dfe dff dfi dfo dfs di- dia dib did die dif dii dio dis doa dob dod doe dof doi doo dos dsa dsb dsd dse dsf dsi dso dss eaa eab ead eae eaf eai eao eas eba ebb ebd ebe ebf ebi ebo ebs ed- eda edb edd ede edf edi edo eds eea eeb eed eee eef eeo ees ef- efa efb efd efe eff efi efo efs eia eib eid eie eif eii eio eis eo- eoa eob eod eoe eof eoi eoo eos es- esa esb esd ese esf esi eso ess faa fab fad fae faf fai fao fas fba fbb fbd fbe fbf fbi fbo fbs fda fdb fdd fde fdf fdi fdo fds fea feb fed fee fef fei feo fes ffa ffd ffe fff ffi ffo ffs fia fib fid fie fif fii fis foa fob foe fof foi foo fos fsa fsb fsd fse fsf fsi fso fss i-d i-f ia- iaa iab iad iae iaf iai iao ias iba ibb ibd ibe ibf ibi ibo ibs ida idb idd ide idf idi ido ids ie- iea ied iee ief iei ies ifa ifb ifd ife iff ifi ifo ifs iia iib iid iie iif iii iio iis io- ioa iob iod ioe iof ioi ioo ios is- isa isb isd ise isf isi iso iss o-i oaa oab oad oae oaf oai oao oas ob- oba obb obd obe obf obi obo obs oda odb odd ode odf odi odo ods oea oeb oed oee oef oei oeo oes of- ofa ofb ofd ofe off ofi ofo ofs oia oib oid oie oif oii oio ois oo- ooa oob ood oof ooi ooo oos os- osa osb osd ose osf osi oso oss saa sab sad sae saf sai sao sas sba sbb sbd sbe sbf sbi sbo sbs sda sdb sdd sde sdf sdi sdo sds se- sea seb sed see sef sei seo ses sfa sfb sfd sfe sff sfi sfo sfs sia sib sid sie sif sii sio sis soa sob sod soe sof soi soo sos ss- ssa ssb ssd sse ssf ssi sso sss