a-a a-b a-t a-z aaa aab aae aaf aan aat aaz ab- aba abb abe abf abn abt abz aea aeb aee aef aen aet aez af- afa afb afe aff afn aft afz an- ana anb ane anf ann ant anz at- ata atb ate atf atn att atz az- aza azb aze azf azn azt azz baa bab bae baf ban bat baz bba bbb bbe bbf bbn bbt be- bea beb bee bef ben bet bez bfa bfb bfe bff bfn bft bfz bna bnb bne bnf bnn bnt bnz bta btb bte btf btn btt btz bza bze bzf bzn bzz eaa eab eae eaf ean eat eaz eba ebb ebe ebf ebn ebt eea eeb eee eef een eet ef- efa efb efe eff eft en- ena enb ene enf enn ent enz eta etb ete etf etn ett etz eze ezf ezz faa fab fae faf fan fat faz fba fbb fbe fbf fbn fbt fea feb fee fef fen fet fez ffa ffe fff ffn fft ffz fna fnb fne fnf fnn fnt fnz fta ftb fte ftf ftn ftt ftz naa nab nae naf nan nat naz nba nbb nbe nbf nbn nbt ne- nea neb nee nef nen net nez nfa nfb nfe nff nfn nft nna nnb nne nnf nnn nnt nnz nta ntb nte ntf ntn ntt ntz nzb nze nzf nzz taa tab tae taf tan tat taz tba tbb tbe tbf tbn tbt tbz te- tea teb tee tef ten tet tez tfa tfb tfe tff tfn tft tna tnb tne tnf tnn tnt tnz tta ttb tte ttf ttn ttt tza tze tzf zaa zab zaf zan zat zaz zbb zbt zea zeb zee zef zen zet zez zfa zfn zne znn zta zte zzt zzz