-ic a-a a-b a-c a-i aaa aab aac aad aai aao aas ab- aba abb abc abd abi abo abs ac- aca acb acc acd aci aco acs ad- ada adb adc add adi ado ads ai- aia aib aic aid aii aio ais aoa aob aoc aod aoi aoo aos as- asa asb asc asd asi aso ass baa bab bac bad bai bao bas bba bbb bbc bbd bbi bbo bbs bca bcb bcc bcd bci bco bcs bda bdb bdc bdd bdi bdo bds bi- bia bib bic bid bii bio bis boa bob boc bod boi boo bos bsa bsb bsc bsd bsi bso bss c-- caa cab cac cad cai cao cas cba cbb cbc cbd cbi cbo cbs cca ccb ccc ccd cci cco ccs cda cdb cdc cdd cdi cdo cds ci- cia cib cic cid cii cio cis co- coa cob coc cod coi coo cos csa csb csc csd csi cso css daa dab dac dad dai dao das dba dbb dbc dbd dbi dbo dbs dca dcb dcc dcd dci dco dcs dda ddb ddc ddd ddi ddo dds di- dia dib dic did dii dio dis doa dob doc dod doi doo dos dsa dsb dsc dsd dsi dso dss i-d ia- iaa iab iac iad iai iao ias iba ibb ibc ibd ibi ibo ibs ica icb icc icd ici ico ics ida idb idc idd idi ido ids iia iib iic iid iii iio iis io- ioa iob ioc iod ioi ioo ios is- isa isb isc isd isi iso iss o-i oaa oab oac oad oai oao oas ob- oba obb obc obd obi obo obs oc- oca ocb occ ocd oci oco ocs oda odb odc odd odi odo ods oia oib oic oid oii oio ois oo- ooa oob ooc ood ooi ooo oos os- osa osb osc osd osi oso oss saa sab sac sad sai sao sas sba sbb sbc sbd sbi sbo sbs sca scb scc scd sci sco scs sda sdb sdc sdd sdi sdo sds sia sib sic sid sii sio sis soa sob soc sod soi soo sos ss- ssa ssb ssc ssd ssi sso sss