a-a a-b aaa aab aad aaf aan aao aar aas aau ab- aba abb abd abf abn abo abr abs abu ad- ada adb add adf adn ado adr ads adu af- afa afb afd aff afn afo afr afs afu an- ana anb and anf ann ano anr ans anu aoa aob aod aof aon aoo aor aos aou ar- ara arb ard arf arn aro arr ars aru as- asa asb asd asf asn aso asr ass asu au- aua aub aud auf aun auo aur aus b-u baa bab bad baf ban bao bar bas bau bba bbb bbd bbf bbn bbo bbr bbs bbu bda bdb bdd bdf bdo bdr bds bdu bfa bfb bfd bff bfn bfo bfr bfs bfu bna bnb bnd bnf bnn bno bnr bns bnu boa bob bod bof bon boo bor bos bou bra brb brd brf brn bro brr brs bru bsa bsb bsd bsf bsn bso bsr bss bsu bua bub bud buf bun buo bur bus buu daa dab dad daf dan dao dar das dau dba dbb dbd dbf dbn dbo dbr dbs dbu dda ddb ddd ddf ddn ddo ddr dds ddu dfa dfb dfd dff dfn dfo dfr dfs dfu dna dnb dnd dnf dnn dno dnr dns doa dob dod dof don doo dor dos dou dra drb drd drn dro drr drs dru dsa dsb dsd dsf dsn dso dsr dss dsu dua dub dud duf dun duo dur dus faa fab fad faf fan fao far fas fau fba fbb fbd fbf fbn fbo fbr fbs fbu fda fdb fdd fdf fdn fdo fdr fds fdu ffa ffd fff ffn ffo ffr ffs ffu fna fnb fnd fnf fnn fnr fns fnu foa fob fof fon foo for fos fou fra frb frd frf frn fro frr frs fru fsa fsb fsd fsf fsn fso fsr fss fsu fua fub fud fuf fun fuo fur fus fuu naa nab nad naf nan nao nar nas nau nba nbb nbd nbf nbn nbo nbr nbs nbu nda ndb ndd ndf ndn ndo ndr nds ndu nfa nfb nfd nff nfn nfo nfr nfs nfu nna nnb nnf nnn nno nns nnu no- noa nob nod nof non noo nor nos nou nra nrb nrd nrf nrn nro nrr nrs nru nsa nsb nsd nsf nsn nso nsr nss nsu nua nub nud nun nuo nur nus nuu oaa oab oad oaf oan oao oar oas oau ob- oba obb obd obf obn obo obr obs obu oda odb odd odf odn odo odr ods odu of- ofa ofb ofd off ofn ofo ofr ofs ofu on- ona onb ond onf onn ono onr ons onu oo- ooa oob ood oof oon ooo oor oos or- ora orb ord orf orn oro orr ors oru os- osa osb osd osf osn oso osr oss osu ou- oua oud ouf oun ouo our ous ra- raa rab rad raf ran rao rar ras rau rba rbb rbd rbf rbn rbo rbr rbs rbu rda rdb rdd rdf rdn rdo rdr rds rdu rfa rfb rfd rff rfn rfo rfr rfs rfu rna rnb rnd rnn rno rnr rns rnu roa rob rod rof ron roo ror ros rou rra rrb rrd rrf rrn rrr rrs rru rsa rsb rsd rsf rsn rso rsr rss rsu rua rub rud ruf run ruo rur rus ruu saa sab sad saf san sao sar sas sau sba sbb sbd sbf sbn sbo sbr sbs sbu sda sdb sdd sdf sdn sdo sdr sds sdu sfa sfb sfd sff sfn sfo sfr sfs sfu sna snb snd snf snn sno snr sns snu soa sob sod sof son soo sor sos sou sr- sra srb srd srf srn sro srr srs ss- ssa ssb ssd ssf ssn sso ssr sss ssu sua sub sud suf sun suo sur sus suu ua- uaa uab uad uaf uan uao uar uas uau uba ubb ubf ubn ubo ubr ubs ubu uda udb udd udf udn udo udr uds udu ufa ufd uff ufn ufo ufr ufs ufu un- una unb und unf unn uno unr uns unu uoa uob uod uon uoo uor uos ur- ura urb urd urf urn uro urr urs uru usa usb usd usf usn uso usr uss usu uua uun uur uus uuu