-ic bbb bbc bbi bbk bbo bby bcb bcc bci bck bco bcy bi- bib bic bii bik bio biy bkb bkc bkk bko bob boc boi bok boo boy by- byc byi byk byo c-- cbb cbc cbi cbk cbo cby ccb ccc cci cck cco ci- cib cic cii cik cio ckb ckc cki cko cky co- cob coc coi cok coo coy cyb cyc cyk cyo ibb ibc ibi ibk ibo iby icb icc ici ick ico icy iib iic iii iio ikb ikc iki ikk iko io- iob ioc ioi ioo iyc iyo iyy kbb kbc kbi kbk kbo kcb kcc kci kck kib kic kii kik kio kkb kkc kki kkk kky kob koc koi kok koo koy kyc kyo o-i ob- obb obc obi obk obo oby oc- ocb occ oci ock oco oib oic oii oik oio okb okc oki okk oko oo- oob ooc ooi ook ooo oyi oyo ybc ybi yby ycc yci yco ycy yii yio yki ykk yob yoc yoi yok yoo yoy yyb yyc yyy