a-a a-b a-z aaa aab aak aas aaz ab- aba abb abk abs abz aka akb akk aks as- asa asb ask ass asz az- aza azb azs azz baa bab bak bas baz bba bbb bbk bbs bka bkb bkk bks bsa bsb bsk bss bza bzs bzz k-z ka- kaa kab kak kas kaz kba kbb kbk kbs kbz kkb kkk kks ksa ksb ksk kss saa sab sak sas saz sba sbb sbk sbs sk- ska skb skk sks ss- ssa ssb ssk sss ssz sza zaa zab zak zas zaz zbb zbs zka zks zsa zsz zzs zzz