b-u bbb bbc bbk bbo bbt bbu bcb bcc bck bco bct bcu bkb bkc bkk bko bkt bob boc bok boo bot bou btb btc btk bto btt btu bub buc buk buo but buu c-- cbb cbc cbk cbo cbt cbu ccb ccc cck cco cct ccu ckb ckc cko ckt co- cob coc cok coo cot cou ctb ctc ctk cto ctt ctu cub cuc cuk cuo cut cuu k-t kbb kbc kbk kbo kbu kcb kcc kck kct kcu kkb kkc kkk kkt kku kob koc kok koo kot kou ktb ktc ktk kto ktt ktu kub kuc kuk kut kuu ob- obb obc obk obo obt obu oc- ocb occ ock oco oct ocu okb okc okk oko oku oo- oob ooc ook ooo oot ot- otb otc otk oto ott otu ou- ouc ouk ouo out tbb tbc tbk tbo tbt tbu tcb tcc tck tco tct tcu tkb tkc tkk tko tkt to- tob toc tok too tot tou ttb ttc ttk tto ttt ttu tub tuc tuk tuo tut tuu ubb ubc ubk ubo ubt ubu ucb ucc uck uco uct ucu ukb ukc ukk uku uob uoc uok uoo uot utb utc utk uto utt utu uuc uut uuu