a-a a-b a-t aaa aab aaf aan aao aat aau ab- aba abb abf abn abo abt abu af- afa afb aff afn afo aft afu an- ana anb anf ann ano ant anu aoa aob aof aon aoo aot aou at- ata atb atf atn ato att atu au- aua aub auf aun auo aut b-u baa bab baf ban bao bat bau bba bbb bbf bbn bbo bbt bbu bfa bfb bff bfn bfo bft bfu bna bnb bnf bnn bno bnt bnu boa bob bof bon boo bot bou bta btb btf btn bto btt btu bua bub buf bun buo but buu faa fab faf fan fao fat fau fba fbb fbf fbn fbo fbt fbu ffa fff ffn ffo fft ffu fna fnb fnf fnn fnt fnu foa fob fof fon foo fot fou fta ftb ftf ftn fto ftt ftu fua fub fuf fun fuo fut fuu naa nab naf nan nao nat nau nba nbb nbf nbn nbo nbt nbu nfa nfb nff nfn nfo nft nfu nna nnb nnf nnn nno nnt nnu no- noa nob nof non noo not nou nta ntb ntf ntn nto ntt ntu nua nub nun nuo nut nuu oaa oab oaf oan oao oat oau ob- oba obb obf obn obo obt obu of- ofa ofb off ofn ofo oft ofu on- ona onb onf onn ono ont onu oo- ooa oob oof oon ooo oot ot- ota otb otf otn oto ott otu ou- oua ouf oun ouo out taa tab taf tan tao tat tau tba tbb tbf tbn tbo tbt tbu tfa tfb tff tfn tfo tft tfu tna tnb tnf tnn tno tnt to- toa tob tof ton too tot tou tta ttb ttf ttn tto ttt ttu tua tub tuf tun tuo tut tuu ua- uaa uab uaf uan uao uat uau uba ubb ubf ubn ubo ubt ubu ufa uff ufn ufo uft ufu un- una unb unf unn uno unt unu uoa uob uon uoo uot uta utb utf utn uto utt utu uua uun uut uuu