-ic a-a a-b a-c a-i aaa aab aac aad aai aas ab- aba abb abc abd abi abs ac- aca acb acc acd aci acs ad- ada adb adc add adi ads ai- aia aib aic aid aii ais as- asa asb asc asd asi ass baa bab bac bad bai bas bba bbb bbc bbd bbi bbs bca bcb bcc bcd bci bcs bda bdb bdc bdd bdi bds bi- bia bib bic bid bii bis bsa bsb bsc bsd bsi bss c-- caa cab cac cad cai cas cba cbb cbc cbd cbi cbs cca ccb ccc ccd cci ccs cda cdb cdc cdd cdi cds ci- cia cib cic cid cii cis csa csb csc csd csi css daa dab dac dad dai das dba dbb dbc dbd dbi dbs dca dcb dcc dcd dci dcs dda ddb ddc ddd ddi dds di- dia dib dic did dii dis dsa dsb dsc dsd dsi dss i-d ia- iaa iab iac iad iai ias iba ibb ibc ibd ibi ibs ica icb icc icd ici ics ida idb idc idd idi ids iia iib iic iid iii iis is- isa isb isc isd isi iss saa sab sac sad sai sas sba sbb sbc sbd sbi sbs sca scb scc scd sci scs sda sdb sdc sdd sdi sds sia sib sic sid sii sis ss- ssa ssb ssc ssd ssi sss