bbb bbc bbk bbn bbo bbx bcb bcc bck bcn bco bcx bkb bkc bkk bkn bko bkx bnb bnc bnk bnn bno bnx bob boc bok bon boo box bxb bxn bxo bxx c-- cbb cbc cbk cbn cbo cbx ccb ccc cck ccn cco ccx ckb ckc cko ckx cn- cnb cnc cnn cno cnx co- cob coc cok con coo cox cxc cxk cxo cxx kbb kbc kbk kbn kbo kbx kcb kcc kck kcn kcx kkb kkc kkk kkn kn- knc knk knn kno knx kob koc kok kon koo kxo nbb nbc nbk nbn nbo nbx ncb ncc nck ncn nco ncx nkc nkk nkn nko nnb nnc nnk nnn nno no- nob noc nok non noo nox nxc ob- obb obc obk obn obo obx oc- ocb occ ock ocn oco ocx okb okc okk oko on- onb onc onk onn ono onx oo- oob ooc ook oon ooo oox ox- oxb oxc oxn oxo oxx xbc xbx xcb xcx xkb xnc xnk xno xoc xok xon xoo xox xxo xxx