b-u bbb bbc bbo bbt bbu bby bcb bcc bco bct bcu bcy bob boc boo bot bou boy btb btc bto btt btu bty bub buc buo but buu buy by- byc byo byt byu c-- cbb cbc cbo cbt cbu cby ccb ccc cco cct ccu co- cob coc coo cot cou coy ctb ctc cto ctt ctu cty cub cuc cuo cut cuu cuy cyb cyc cyo cyt ob- obb obc obo obt obu oby oc- ocb occ oco oct ocu oo- oob ooc ooo oot ot- otb otc oto ott otu ou- ouc ouo out oyo tbb tbc tbo tbt tbu tcb tcc tco tct tcu to- tob toc too tot tou toy ttb ttc tto ttt ttu tty tub tuc tuo tut tuu tuy tyc tyo tyt ubb ubc ubo ubt ubu uby ucb ucc uco uct ucu uob uoc uoo uot utb utc uto utt utu uty uuc uut uuu uyc uyo uyu ybc yby ycc yco ycu ycy yob yoc yoo yot you yoy ytc yto ytt ytu yuo yut yuu yuy yyb yyc yyt yyu yyy