-ic a-a a-b a-c a-i aaa aab aac aad aai aak aas ab- aba abb abc abd abi abk abs ac- aca acb acc acd aci ack acs ad- ada adb adc add adi adk ads ai- aia aib aic aid aii aik ais aka akb akc akd aki akk aks as- asa asb asc asd asi ask ass baa bab bac bad bai bak bas bba bbb bbc bbd bbi bbk bbs bca bcb bcc bcd bci bck bcs bda bdb bdc bdd bdi bdk bds bi- bia bib bic bid bii bik bis bka bkb bkc bkk bks bsa bsb bsc bsd bsi bsk bss c-- caa cab cac cad cai cak cas cba cbb cbc cbd cbi cbk cbs cca ccb ccc ccd cci cck ccs cda cdb cdc cdd cdi cdk cds ci- cia cib cic cid cii cik cis cka ckb ckc ckd cki cks csa csb csc csd csi csk css daa dab dac dad dai dak das dba dbb dbc dbd dbi dbk dbs dca dcb dcc dcd dci dck dcs dda ddb ddc ddd ddi ddk dds di- dia dib dic did dii dik dis dka dkb dkc dki dkk dks dsa dsb dsc dsd dsi dsk dss i-d ia- iaa iab iac iad iai ias iba ibb ibc ibd ibi ibk ibs ica icb icc icd ici ick ics ida idb idc idd idi idk ids iia iib iic iid iii iis ika ikb ikc iki ikk iks is- isa isb isc isd isi isk iss ka- kaa kab kac kad kai kak kas kba kbb kbc kbd kbi kbk kbs kca kcb kcc kcd kci kck kcs kda kdb kdc kdk kds kia kib kic kid kii kik kis kkb kkc kki kkk kks ksa ksb ksc ksd ksi ksk kss saa sab sac sad sai sak sas sba sbb sbc sbd sbi sbk sbs sca scb scc scd sci sck scs sda sdb sdc sdd sdi sdk sds sia sib sic sid sii sik sis sk- ska skb skc skd ski skk sks ss- ssa ssb ssc ssd ssi ssk sss