bbb bbc bbd bbk bbn bbo bcb bcc bcd bck bcn bco bdb bdc bdd bdk bdo bkb bkc bkk bkn bko bnb bnc bnd bnk bnn bno bob boc bod bok bon boo c-- cbb cbc cbd cbk cbn cbo ccb ccc ccd cck ccn cco cdb cdc cdd cdk cdn cdo ckb ckc ckd cko cn- cnb cnc cnd cnn cno co- cob coc cod cok con coo dbb dbc dbd dbk dbn dbo dcb dcc dcd dck dcn dco ddb ddc ddd ddk ddn ddo dkb dkc dkk dko dnb dnc dnd dnk dnn dno dob doc dod dok don doo kbb kbc kbd kbk kbn kbo kcb kcc kcd kck kcn kdb kdc kdk kdo kkb kkc kkk kkn kn- knc knd knk knn kno kob koc kod kok kon koo nbb nbc nbd nbk nbn nbo ncb ncc ncd nck ncn nco ndb ndc ndd ndk ndn ndo nkc nkk nkn nko nnb nnc nnk nnn nno no- nob noc nod nok non noo ob- obb obc obd obk obn obo oc- ocb occ ocd ock ocn oco odb odc odd odn odo okb okc okd okk oko on- onb onc ond onk onn ono oo- oob ooc ood ook oon ooo