-ic bbb bbc bbd bbi bbk bbo bcb bcc bcd bci bck bco bdb bdc bdd bdi bdk bdo bi- bib bic bid bii bik bio bkb bkc bkk bko bob boc bod boi bok boo c-- cbb cbc cbd cbi cbk cbo ccb ccc ccd cci cck cco cdb cdc cdd cdi cdk cdo ci- cib cic cid cii cik cio ckb ckc ckd cki cko co- cob coc cod coi cok coo dbb dbc dbd dbi dbk dbo dcb dcc dcd dci dck dco ddb ddc ddd ddi ddk ddo di- dib dic did dii dik dio dkb dkc dki dkk dko dob doc dod doi dok doo i-d ibb ibc ibd ibi ibk ibo icb icc icd ici ick ico idb idc idd idi idk ido iib iic iid iii iio ikb ikc iki ikk iko io- iob ioc iod ioi ioo kbb kbc kbd kbi kbk kbo kcb kcc kcd kci kck kdb kdc kdk kdo kib kic kid kii kik kio kkb kkc kki kkk kob koc kod koi kok koo o-i ob- obb obc obd obi obk obo oc- ocb occ ocd oci ock oco odb odc odd odi odo oib oic oid oii oik oio okb okc okd oki okk oko oo- oob ooc ood ooi ook ooo