bbb bbc bbd bbn bbo bbs bcb bcc bcd bcn bco bcs bdb bdc bdd bdo bds bnb bnc bnd bnn bno bns bob boc bod bon boo bos bsb bsc bsd bsn bso bss c-- cbb cbc cbd cbn cbo cbs ccb ccc ccd ccn cco ccs cdb cdc cdd cdn cdo cds cn- cnb cnc cnd cnn cno cns co- cob coc cod con coo cos csb csc csd csn cso css dbb dbc dbd dbn dbo dbs dcb dcc dcd dcn dco dcs ddb ddc ddd ddn ddo dds dnb dnc dnd dnn dno dns dob doc dod don doo dos dsb dsc dsd dsn dso dss nbb nbc nbd nbn nbo nbs ncb ncc ncd ncn nco ncs ndb ndc ndd ndn ndo nds nnb nnc nnn nno nns no- nob noc nod non noo nos nsb nsc nsd nsn nso nss ob- obb obc obd obn obo obs oc- ocb occ ocd ocn oco ocs odb odc odd odn odo ods on- onb onc ond onn ono ons oo- oob ooc ood oon ooo oos os- osb osc osd osn oso oss sbb sbc sbd sbn sbo sbs scb scc scd scn sco scs sdb sdc sdd sdn sdo sds snb snc snd snn sno sns sob soc sod son soo sos ss- ssb ssc ssd ssn sso sss