a-a a-b a-i aaa aab aad aaf aai aao aar aas ab- aba abb abd abf abi abo abr abs ad- ada adb add adf adi ado adr ads af- afa afb afd aff afi afo afr afs ai- aia aib aid aif aii aio air ais aoa aob aod aof aoi aoo aor aos ar- ara arb ard arf ari aro arr ars as- asa asb asd asf asi aso asr ass baa bab bad baf bai bao bar bas bba bbb bbd bbf bbi bbo bbr bbs bda bdb bdd bdf bdi bdo bdr bds bfa bfb bfd bff bfi bfo bfr bfs bi- bia bib bid bif bii bio bir bis boa bob bod bof boi boo bor bos bra brb brd brf bri bro brr brs bsa bsb bsd bsf bsi bso bsr bss daa dab dad daf dai dao dar das dba dbb dbd dbf dbi dbo dbr dbs dda ddb ddd ddf ddi ddo ddr dds dfa dfb dfd dff dfi dfo dfr dfs di- dia dib did dif dii dio dir dis doa dob dod dof doi doo dor dos dra drb drd dri dro drr drs dsa dsb dsd dsf dsi dso dsr dss faa fab fad faf fai fao far fas fba fbb fbd fbf fbi fbo fbr fbs fda fdb fdd fdf fdi fdo fdr fds ffa ffd fff ffi ffo ffr ffs fia fib fid fif fii fir fis foa fob fof foi foo for fos fra frb frd frf fri fro frr frs fsa fsb fsd fsf fsi fso fsr fss i-d i-f ia- iaa iab iad iaf iai iao iar ias iba ibb ibd ibf ibi ibo ibr ibs ida idb idd idf idi ido idr ids ifa ifb ifd iff ifi ifo ifr ifs iia iib iid iif iii iio iir iis io- ioa iob iod iof ioi ioo ior ios ir- ira irb ird irf iri iro irr irs is- isa isb isd isf isi iso isr iss o-i oaa oab oad oaf oai oao oar oas ob- oba obb obd obf obi obo obr obs oda odb odd odf odi odo odr ods of- ofa ofb ofd off ofi ofo ofr ofs oia oib oid oif oii oio oir ois oo- ooa oob ood oof ooi ooo oor oos or- ora orb ord orf ori oro orr ors os- osa osb osd osf osi oso osr oss ra- raa rab rad raf rai rao rar ras rba rbb rbd rbf rbi rbo rbr rbs rda rdb rdd rdf rdi rdo rdr rds rfa rfb rfd rff rfi rfo rfr rfs ria rib rid rif rii rio rir ris roa rob rod rof roi roo ror ros rra rrb rrd rrf rri rrr rrs rsa rsb rsd rsf rsi rso rsr rss saa sab sad saf sai sao sar sas sba sbb sbd sbf sbi sbo sbr sbs sda sdb sdd sdf sdi sdo sdr sds sfa sfb sfd sff sfi sfo sfr sfs sia sib sid sif sii sio sir sis soa sob sod sof soi soo sor sos sr- sra srb srd srf sri sro srr srs ss- ssa ssb ssd ssf ssi sso ssr sss