a-a a-b aaa aab aad aaf aan aao aar aau aax ab- aba abb abd abf abn abo abr abu abx ad- ada adb add adf adn ado adr adu adx af- afa afb afd aff afn afo afr afu afx an- ana anb and anf ann ano anr anu anx aoa aob aod aof aon aoo aor aou aox ar- ara arb ard arf arn aro arr aru arx au- aua aub aud auf aun auo aur aux ax- axa axn axo axr axx b-u baa bab bad baf ban bao bar bau bax bba bbb bbd bbf bbn bbo bbr bbu bbx bda bdb bdd bdf bdo bdr bdu bdx bfa bfb bfd bff bfn bfo bfr bfu bfx bna bnb bnd bnf bnn bno bnr bnu bnx boa bob bod bof bon boo bor bou box bra brb brd brf brn bro brr bru brx bua bub bud buf bun buo bur buu bux bxb bxd bxn bxo bxx daa dab dad daf dan dao dar dau dax dba dbb dbd dbf dbn dbo dbr dbu dbx dda ddb ddd ddf ddn ddo ddr ddu ddx dfa dfb dfd dff dfn dfo dfr dfu dfx dna dnb dnd dnf dnn dno dnr doa dob dod dof don doo dor dou dox dra drb drd drn dro drr dru drx dua dub dud duf dun duo dur dux dxd dxn dxo dxr dxx faa fab fad faf fan fao far fau fax fba fbb fbd fbf fbn fbo fbr fbu fbx fda fdb fdd fdf fdn fdo fdr fdu fdx ffa ffd fff ffn ffo ffr ffu ffx fna fnb fnd fnf fnn fnr fnu fnx foa fob fof fon foo for fou fox fra frb frd frf frn fro frr fru fua fub fud fuf fun fuo fur fuu fux fxr fxu fxx naa nab nad naf nan nao nar nau nax nba nbb nbd nbf nbn nbo nbr nbu nbx nda ndb ndd ndf ndn ndo ndr ndu nfa nfb nfd nff nfn nfo nfr nfu nna nnb nnf nnn nno nnu no- noa nob nod nof non noo nor nou nox nra nrb nrd nrf nrn nro nrr nru nrx nua nub nud nun nuo nur nuu nux nxd oaa oab oad oaf oan oao oar oau oax ob- oba obb obd obf obn obo obr obu obx oda odb odd odf odn odo odr odu of- ofa ofb ofd off ofn ofo ofr ofu ofx on- ona onb ond onf onn ono onr onu onx oo- ooa oob ood oof oon ooo oor oox or- ora orb ord orf orn oro orr oru orx ou- oua oud ouf oun ouo our ox- oxa oxb oxf oxn oxo oxx ra- raa rab rad raf ran rao rar rau rax rba rbb rbd rbf rbn rbo rbr rbu rbx rda rdb rdd rdf rdn rdo rdr rdu rdx rfa rfb rfd rff rfn rfo rfr rfu rna rnb rnd rnn rno rnr rnu roa rob rod rof ron roo ror rou rox rra rrb rrd rrf rrn rrr rru rua rub rud ruf run ruo rur ruu rux rxr ua- uaa uab uad uaf uan uao uar uau uba ubb ubf ubn ubo ubr ubu ubx uda udb udd udf udn udo udr udu udx ufa ufd uff ufn ufo ufr ufu ufx un- una unb und unf unn uno unr unu unx uoa uob uod uon uoo uor uox ur- ura urb urd urf urn uro urr uru urx uua uun uur uuu uxb uxf uxo uxr uxu xaa xad xaf xan xar xau xbr xbx xda xdb xdf xdr xfa xfn xfx xna xno xnu xoa xod xof xon xoo xor xox xrd xrf xrx xun xxo xxx