a-a a-b a-i a-z aaa aab aaf aai aan aao aaz ab- aba abb abf abi abn abo abz af- afa afb aff afi afn afo afz ai- aia aib aif aii ain aio aiz an- ana anb anf ani ann ano anz aoa aob aof aoi aon aoo az- aza azb azf azi azn azo azz baa bab baf bai ban bao baz bba bbb bbf bbi bbn bbo bfa bfb bff bfi bfn bfo bfz bi- bia bib bif bii bin bio biz bna bnb bnf bni bnn bno bnz boa bob bof boi bon boo boz bza bzf bzn bzo bzz faa fab faf fai fan fao faz fba fbb fbf fbi fbn fbo ffa fff ffi ffn ffo ffz fia fib fif fii fin fiz fna fnb fnf fni fnn fnz foa fob fof foi fon foo foz i-f ia- iaa iab iaf iai ian iao iaz iba ibb ibf ibi ibn ibo ibz ifa ifb iff ifi ifn ifo ifz iia iib iif iii iin iio in- ina inb inf ini inn ino io- ioa iob iof ioi ion ioo iza izi izo izz n-i naa nab naf nai nan nao naz nba nbb nbf nbi nbn nbo nfa nfb nff nfi nfn nfo nia nib nif nii nin nio niz nna nnb nnf nni nnn nno nnz no- noa nob nof noi non noo noz nzb nzf nzi nzo nzz o-i oaa oab oaf oai oan oao ob- oba obb obf obi obn obo of- ofa ofb off ofi ofn ofo ofz oia oib oif oii oin oio oiz on- ona onb onf oni onn ono oo- ooa oob oof ooi oon ooo oza ozo ozz zaa zab zaf zai zan zao zaz zbb zfa zfn zia zib zif zin zio ziz znn zno zo- zoa zob zof zoi zon zoo zzz