a-a a-b a-z aaa aab aah aar aaz ab- aba abb abh abr abz aha ahb ahh ahr ahz ar- ara arb arh arr arz az- aza azb azz baa bab bah bar baz bba bbb bbh bbr bha bhb bhh bhr bra brb brh brr brz bza bzh bzr bzz haa hab hah har haz hba hbb hbh hbr hbz hha hhb hhh hhr hhz hr- hra hrb hrh hrr hrz ra- raa rab rah rar raz rba rbb rbh rbr rh- rha rhb rhh rhr rra rrb rrh rrr rza rzb zaa zab zah zar zaz zbb zbr zha zhr zrh zzr zzz