a-a a-b a-c a-z aaa aab aac aan aao aau aaz ab- aba abb abc abn abo abu abz ac- aca acb acc acn aco acu acz an- ana anb anc ann ano anu anz aoa aob aoc aon aoo aou au- aua aub auc aun auo auz az- aza azb azn azo azu azz b-u baa bab bac ban bao bau baz bba bbb bbc bbn bbo bbu bca bcb bcc bcn bco bcu bcz bna bnb bnc bnn bno bnu bnz boa bob boc bon boo bou boz bua bub buc bun buo buu buz bza bzn bzo bzu bzz c-- caa cab cac can cao cau caz cba cbb cbc cbn cbo cbu cbz cca ccb ccc ccn cco ccu ccz cn- cna cnb cnc cnn cno cnu co- coa cob coc con coo cou coz cua cub cuc cun cuo cuu cuz cz- czc czo naa nab nac nan nao nau naz nba nbb nbc nbn nbo nbu nca ncb ncc ncn nco ncu nna nnb nnc nnn nno nnu nnz no- noa nob noc non noo nou noz nua nub nuc nun nuo nuu nzb nzo nzz oaa oab oac oan oao oau ob- oba obb obc obn obo obu oc- oca ocb occ ocn oco ocu ocz on- ona onb onc onn ono onu oo- ooa oob ooc oon ooo ou- oua ouc oun ouo oza ozo ozu ozz ua- uaa uab uac uan uao uau uaz uba ubb ubc ubn ubo ubu uca ucb ucc ucn uco ucu un- una unb unc unn uno unu uoa uob uoc uon uoo uua uuc uun uuu uza uzb uzo uzu zaa zab zac zan zao zaz zbb zbc zco znc znn zno zo- zoa zob zoc zon zoo zou zub zuc zun zuz zzz