-ic a-a a-b a-c a-i aaa aab aac aad aai aao ab- aba abb abc abd abi abo ac- aca acb acc acd aci aco ad- ada adb adc add adi ado ai- aia aib aic aid aii aio aoa aob aoc aod aoi aoo baa bab bac bad bai bao bba bbb bbc bbd bbi bbo bca bcb bcc bcd bci bco bda bdb bdc bdd bdi bdo bi- bia bib bic bid bii bio boa bob boc bod boi boo c-- caa cab cac cad cai cao cba cbb cbc cbd cbi cbo cca ccb ccc ccd cci cco cda cdb cdc cdd cdi cdo ci- cia cib cic cid cii cio co- coa cob coc cod coi coo daa dab dac dad dai dao dba dbb dbc dbd dbi dbo dca dcb dcc dcd dci dco dda ddb ddc ddd ddi ddo di- dia dib dic did dii dio doa dob doc dod doi doo i-d ia- iaa iab iac iad iai iao iba ibb ibc ibd ibi ibo ica icb icc icd ici ico ida idb idc idd idi ido iia iib iic iid iii iio io- ioa iob ioc iod ioi ioo o-i oaa oab oac oad oai oao ob- oba obb obc obd obi obo oc- oca ocb occ ocd oci oco oda odb odc odd odi odo oia oib oic oid oii oio oo- ooa oob ooc ood ooi ooo