a-a a-b a-i a-t a-z aaa aab aai aak aao aat aaz ab- aba abb abi abk abo abt abz ai- aia aib aii aik aio ait aiz aka akb aki akk ako aoa aob aoi aok aoo aot at- ata atb ati ato att atz az- aza azb azi azo azt azz baa bab bai bak bao bat baz bba bbb bbi bbk bbo bbt bi- bia bib bii bik bio bit biz bka bkb bkk bko bkt boa bob boi bok boo bot boz bta btb bti btk bto btt btz bza bzo bzz ia- iaa iab iai iao iat iaz iba ibb ibi ibk ibo ibt ibz iia iib iii iio iit ika ikb iki ikk iko ikt io- ioa iob ioi ioo iot ita itb iti itk ito itt itz iza izi izo izz k-t k-z ka- kaa kab kai kak kao kat kaz kba kbb kbi kbk kbo kbz kia kib kii kik kio kit kiz kkb kki kkk kkt koa kob koi kok koo kot koz kta ktb ktk kto ktt kzo o-i oaa oab oai oak oao oat ob- oba obb obi obk obo obt oia oib oii oik oio oit oiz oka okb oki okk oko oo- ooa oob ooi ook ooo oot ot- ota otb oti otk oto ott otz oza ozo ozt ozz taa tab tai tak tao tat taz tba tbb tbi tbk tbo tbt tbz tia tib tii tik tio tit tiz tka tkb tkk tko tkt tkz to- toa tob toi tok too tot toz tta ttb tti ttk tto ttt tza zaa zab zai zak zao zat zaz zbb zbt zia zib zik zio zit ziz zka zo- zoa zob zoi zok zoo zot zta zzt zzz