b-u bbb bbc bbo bbu bbx bcb bcc bco bcu bcx bob boc boo bou box bub buc buo buu bux bxb bxo bxx c-- cbb cbc cbo cbu cbx ccb ccc cco ccu ccx co- cob coc coo cou cox cub cuc cuo cuu cxc cxo cxx ob- obb obc obo obu obx oc- ocb occ oco ocu ocx oo- oob ooc ooo oox ou- ouc ouo ox- oxb oxc oxo oxx ubb ubc ubo ubu ubx ucb ucc uco ucu uob uoc uoo uox uuc uuu uxb uxc uxo uxu xbc xbx xcb xcx xoc xoo xox xxo xxx