bbb bbm bbn bbo bbs bmb bmm bmn bmo bms bnb bnn bno bns bob bom bon boo bos bsb bsm bsn bso bss m-o mbb mbm mbo mbs mmb mmm mmn mmo mms mnb mnm mnn mno mns mob mom mon moo mos msb msm msn mso mss nbb nbm nbn nbo nbs nmb nmm nmn nmo nms nnb nnm nnn nno nns no- nob nom non noo nos nsb nsm nsn nso nss ob- obb obm obn obo obs om- omb omm omn omo oms on- onb onn ono ons oo- oob oom oon ooo oos os- osb osm osn oso oss sbb sbm sbn sbo sbs smb smm smn smo sms snb snm snn sno sns sob som son soo sos ss- ssb ssm ssn sso sss