b-u bbb bbc bbf bbk bbt bbu bcb bcc bcf bck bct bcu bfb bfc bff bft bfu bkb bkc bkf bkk bkt btb btc btf btk btt btu bub buc buf buk but buu c-- cbb cbc cbf cbk cbt cbu ccb ccc ccf cck cct ccu cfb cfc cff cfk cft cfu ckb ckc ckt ctb ctc ctf ctk ctt ctu cub cuc cuf cuk cut cuu fbb fbc fbf fbk fbt fbu fcb fcc fcf fck fct fcu ffc fff ffk fft ffu fkb fkc fkf fkk fkt ftb ftc ftf ftk ftt ftu fub fuf fuk fut fuu k-t kbb kbc kbf kbk kbu kcb kcc kck kct kcu kfc kff kfu kkb kkc kkk kkt kku ktb ktc ktf ktk ktt ktu kub kuc kuk kut kuu tbb tbc tbf tbk tbt tbu tcb tcc tcf tck tct tcu tfb tfc tff tfk tft tfu tkb tkc tkk tkt ttb ttc ttf ttk ttt ttu tub tuc tuf tuk tut tuu ubb ubc ubf ubk ubt ubu ucb ucc ucf uck uct ucu ufc uff uft ufu ukb ukc ukf ukk uku utb utc utf utk utt utu uuc uut uuu