bbb bbc bbh bbk bbo bby bcb bcc bch bck bco bcy bhb bhc bhh bhk bho bkb bkc bkk bko bob boc boh bok boo boy by- byc byh byk byo c-- cbb cbc cbh cbk cbo cby ccb ccc cch cck cco ch- chb chc chh chk cho chy ckb ckc ckh cko cky co- cob coc coh cok coo coy cyb cyc cyk cyo hbb hbc hbh hbk hbo hby hcb hcc hch hck hco hcy hhb hhc hhh hhk hho hhy hkb hkh hkk hko hob hoc hoh hok hoo hoy hy- hyb hyc hyh hyo hyy kbb kbc kbh kbk kbo kcb kcc kch kck khh khk kho kkb kkc kkh kkk kky kob koc koh kok koo koy kyc kyo ob- obb obc obh obk obo oby oc- ocb occ och ock oco ohc ohh oho okb okc okk oko oo- oob ooc ooh ook ooo oyo ybc yby ycc ych yco ycy yhc ykk yob yoc yok yoo yoy yyb yyc yyy