a-a a-b a-c a-t aaa aab aac aak aat aau ab- aba abb abc abk abt abu ac- aca acb acc ack act acu aka akb akc akk aku at- ata atb atc att atu au- aua aub auc auk aut b-u baa bab bac bak bat bau bba bbb bbc bbk bbt bbu bca bcb bcc bck bct bcu bka bkb bkc bkk bkt bta btb btc btk btt btu bua bub buc buk but buu c-- caa cab cac cak cat cau cba cbb cbc cbk cbt cbu cca ccb ccc cck cct ccu cka ckb ckc ckt cta ctb ctc ctk ctt ctu cua cub cuc cuk cut cuu k-t ka- kaa kab kac kak kat kau kba kbb kbc kbk kbu kca kcb kcc kck kct kcu kkb kkc kkk kkt kku kta ktb ktc ktk ktt ktu kub kuc kuk kut kuu taa tab tac tak tat tau tba tbb tbc tbk tbt tbu tca tcb tcc tck tct tcu tka tkb tkc tkk tkt tta ttb ttc ttk ttt ttu tua tub tuc tuk tut tuu ua- uaa uab uac uak uat uau uba ubb ubc ubk ubt ubu uca ucb ucc uck uct ucu uka ukb ukc ukk uku uta utb utc utk utt utu uua uuc uut uuu