a-a a-b a-c a-t aaa aab aac aak aan aat aau ab- aba abb abc abk abn abt abu ac- aca acb acc ack acn act acu aka akb akc akk akn aku an- ana anb anc ank ann ant anu at- ata atb atc atn att atu au- aua aub auc auk aun aut b-u baa bab bac bak ban bat bau bba bbb bbc bbk bbn bbt bbu bca bcb bcc bck bcn bct bcu bka bkb bkc bkk bkn bkt bna bnb bnc bnk bnn bnt bnu bta btb btc btk btn btt btu bua bub buc buk bun but buu c-- caa cab cac cak can cat cau cba cbb cbc cbk cbn cbt cbu cca ccb ccc cck ccn cct ccu cka ckb ckc ckt cn- cna cnb cnc cnn cnt cnu cta ctb ctc ctk ctn ctt ctu cua cub cuc cuk cun cut cuu k-t ka- kaa kab kac kak kan kat kau kba kbb kbc kbk kbn kbu kca kcb kcc kck kcn kct kcu kkb kkc kkk kkn kkt kku kn- kna knc knk knn knt knu kta ktb ktc ktk ktn ktt ktu kub kuc kuk kun kut kuu naa nab nac nak nan nat nau nba nbb nbc nbk nbn nbt nbu nca ncb ncc nck ncn nct ncu nka nkc nkk nkn nkt nku nna nnb nnc nnk nnn nnt nnu nta ntb ntc ntk ntn ntt ntu nua nub nuc nuk nun nut nuu taa tab tac tak tan tat tau tba tbb tbc tbk tbn tbt tbu tca tcb tcc tck tcn tct tcu tka tkb tkc tkk tkt tna tnb tnc tnk tnn tnt tta ttb ttc ttk ttn ttt ttu tua tub tuc tuk tun tut tuu ua- uaa uab uac uak uan uat uau uba ubb ubc ubk ubn ubt ubu uca ucb ucc uck ucn uct ucu uka ukb ukc ukk ukn uku un- una unb unc unk unn unt unu uta utb utc utk utn utt utu uua uuc uun uut uuu