a-a a-b a-z aaa aab aan aar aau aaz ab- aba abb abn abr abu abz an- ana anb ann anr anu anz ar- ara arb arn arr aru arz au- aua aub aun aur auz az- aza azb azn azu azz b-u baa bab ban bar bau baz bba bbb bbn bbr bbu bna bnb bnn bnr bnu bnz bra brb brn brr bru brz bua bub bun bur buu buz bza bzn bzr bzu bzz naa nab nan nar nau naz nba nbb nbn nbr nbu nna nnb nnn nnu nnz nra nrb nrn nrr nru nrz nua nub nun nur nuu nzb nzz ra- raa rab ran rar rau raz rba rbb rbn rbr rbu rna rnb rnn rnr rnu rnz rra rrb rrn rrr rru rua rub run rur ruu ruz rza rzb ua- uaa uab uan uar uau uaz uba ubb ubn ubr ubu un- una unb unn unr unu ur- ura urb urn urr uru urz uua uun uur uuu uza uzb uzu zaa zab zan zar zaz zbb zbr znn zub zun zur zuz zzr zzz