a-a a-b a-i a-t aaa aab aai aan aao aat ab- aba abb abi abn abo abt ai- aia aib aii ain aio ait an- ana anb ani ann ano ant aoa aob aoi aon aoo aot at- ata atb ati atn ato att baa bab bai ban bao bat bba bbb bbi bbn bbo bbt bi- bia bib bii bin bio bit bna bnb bni bnn bno bnt boa bob boi bon boo bot bta btb bti btn bto btt ia- iaa iab iai ian iao iat iba ibb ibi ibn ibo ibt iia iib iii iin iio iit in- ina inb ini inn ino int io- ioa iob ioi ion ioo iot ita itb iti itn ito itt n-i naa nab nai nan nao nat nba nbb nbi nbn nbo nbt nia nib nii nin nio nit nna nnb nni nnn nno nnt no- noa nob noi non noo not nta ntb nti ntn nto ntt o-i oaa oab oai oan oao oat ob- oba obb obi obn obo obt oia oib oii oin oio oit on- ona onb oni onn ono ont oo- ooa oob ooi oon ooo oot ot- ota otb oti otn oto ott taa tab tai tan tao tat tba tbb tbi tbn tbo tbt tia tib tii tin tio tit tna tnb tni tnn tno tnt to- toa tob toi ton too tot tta ttb tti ttn tto ttt