a-a a-b a-i a-t aaa aab aai aak aan aao aat ab- aba abb abi abk abn abo abt ai- aia aib aii aik ain aio ait aka akb aki akk akn ako an- ana anb ani ank ann ano ant aoa aob aoi aok aon aoo aot at- ata atb ati atn ato att baa bab bai bak ban bao bat bba bbb bbi bbk bbn bbo bbt bi- bia bib bii bik bin bio bit bka bkb bkk bkn bko bkt bna bnb bni bnk bnn bno bnt boa bob boi bok bon boo bot bta btb bti btk btn bto btt ia- iaa iab iai ian iao iat iba ibb ibi ibk ibn ibo ibt iia iib iii iin iio iit ika ikb iki ikk iko ikt in- ina inb ini ink inn ino int io- ioa iob ioi ion ioo iot ita itb iti itk itn ito itt k-t ka- kaa kab kai kak kan kao kat kba kbb kbi kbk kbn kbo kia kib kii kik kin kio kit kkb kki kkk kkn kkt kn- kna kni knk knn kno knt koa kob koi kok kon koo kot kta ktb ktk ktn kto ktt n-i naa nab nai nak nan nao nat nba nbb nbi nbk nbn nbo nbt nia nib nii nik nin nio nit nka nki nkk nkn nko nkt nna nnb nni nnk nnn nno nnt no- noa nob noi nok non noo not nta ntb nti ntk ntn nto ntt o-i oaa oab oai oak oan oao oat ob- oba obb obi obk obn obo obt oia oib oii oik oin oio oit oka okb oki okk oko on- ona onb oni onk onn ono ont oo- ooa oob ooi ook oon ooo oot ot- ota otb oti otk otn oto ott taa tab tai tak tan tao tat tba tbb tbi tbk tbn tbo tbt tia tib tii tik tin tio tit tka tkb tkk tko tkt tna tnb tni tnk tnn tno tnt to- toa tob toi tok ton too tot tta ttb tti ttk ttn tto ttt