a-a a-b a-i aaa aab aad aai aak aas ab- aba abb abd abi abk abs ad- ada adb add adi adk ads ai- aia aib aid aii aik ais aka akb akd aki akk aks as- asa asb asd asi ask ass baa bab bad bai bak bas bba bbb bbd bbi bbk bbs bda bdb bdd bdi bdk bds bi- bia bib bid bii bik bis bka bkb bkk bks bsa bsb bsd bsi bsk bss daa dab dad dai dak das dba dbb dbd dbi dbk dbs dda ddb ddd ddi ddk dds di- dia dib did dii dik dis dka dkb dki dkk dks dsa dsb dsd dsi dsk dss i-d ia- iaa iab iad iai ias iba ibb ibd ibi ibk ibs ida idb idd idi idk ids iia iib iid iii iis ika ikb iki ikk iks is- isa isb isd isi isk iss ka- kaa kab kad kai kak kas kba kbb kbd kbi kbk kbs kda kdb kdk kds kia kib kid kii kik kis kkb kki kkk kks ksa ksb ksd ksi ksk kss saa sab sad sai sak sas sba sbb sbd sbi sbk sbs sda sdb sdd sdi sdk sds sia sib sid sii sik sis sk- ska skb skd ski skk sks ss- ssa ssb ssd ssi ssk sss