bbb bbf bbn bbo bbs bby bfb bff bfn bfo bfs bfy bnb bnf bnn bno bns bob bof bon boo bos boy bsb bsf bsn bso bss bsy by- byf byn byo bys fbb fbf fbn fbo fbs fff ffn ffo ffs ffy fnb fnf fnn fns fob fof fon foo fos foy fsb fsf fsn fso fss fy- fyb fyn fyo nbb nbf nbn nbo nbs nfb nff nfn nfo nfs nnb nnf nnn nno nns no- nob nof non noo nos noy nsb nsf nsn nso nss nsy nyf nyn nyo nys nyy ob- obb obf obn obo obs oby of- ofb off ofn ofo ofs on- onb onf onn ono ons ony oo- oob oof oon ooo oos os- osb osf osn oso oss oyo oys sbb sbf sbn sbo sbs sby sfb sff sfn sfo sfs snb snf snn sno sns sny sob sof son soo sos soy ss- ssb ssf ssn sso sss sy- syb syn sys ybf ybs yby yff yfs ynn yns yny yob yof yon yoo yos yoy ysb yso yss ysy yyb yyf yys yyy