a-a a-b aaa aab aad aaf aan aas aau ab- aba abb abd abf abn abs abu ad- ada adb add adf adn ads adu af- afa afb afd aff afn afs afu an- ana anb and anf ann ans anu as- asa asb asd asf asn ass asu au- aua aub aud auf aun aus b-u baa bab bad baf ban bas bau bba bbb bbd bbf bbn bbs bbu bda bdb bdd bdf bds bdu bfa bfb bfd bff bfn bfs bfu bna bnb bnd bnf bnn bns bnu bsa bsb bsd bsf bsn bss bsu bua bub bud buf bun bus buu daa dab dad daf dan das dau dba dbb dbd dbf dbn dbs dbu dda ddb ddd ddf ddn dds ddu dfa dfb dfd dff dfn dfs dfu dna dnb dnd dnf dnn dns dsa dsb dsd dsf dsn dss dsu dua dub dud duf dun dus faa fab fad faf fan fas fau fba fbb fbd fbf fbn fbs fbu fda fdb fdd fdf fdn fds fdu ffa ffd fff ffn ffs ffu fna fnb fnd fnf fnn fns fnu fsa fsb fsd fsf fsn fss fsu fua fub fud fuf fun fus fuu naa nab nad naf nan nas nau nba nbb nbd nbf nbn nbs nbu nda ndb ndd ndf ndn nds ndu nfa nfb nfd nff nfn nfs nfu nna nnb nnf nnn nns nnu nsa nsb nsd nsf nsn nss nsu nua nub nud nun nus nuu saa sab sad saf san sas sau sba sbb sbd sbf sbn sbs sbu sda sdb sdd sdf sdn sds sdu sfa sfb sfd sff sfn sfs sfu sna snb snd snf snn sns snu ss- ssa ssb ssd ssf ssn sss ssu sua sub sud suf sun sus suu ua- uaa uab uad uaf uan uas uau uba ubb ubf ubn ubs ubu uda udb udd udf udn uds udu ufa ufd uff ufn ufs ufu un- una unb und unf unn uns unu usa usb usd usf usn uss usu uua uun uus uuu