a-a a-b a-i a-t aaa aab aai aan aao aar aat ab- aba abb abi abn abo abr abt ai- aia aib aii ain aio air ait an- ana anb ani ann ano anr ant aoa aob aoi aon aoo aor aot ar- ara arb ari arn aro arr art at- ata atb ati atn ato atr att baa bab bai ban bao bar bat bba bbb bbi bbn bbo bbr bbt bi- bia bib bii bin bio bir bit bna bnb bni bnn bno bnr bnt boa bob boi bon boo bor bot bra brb bri brn bro brr brt bta btb bti btn bto btr btt ia- iaa iab iai ian iao iar iat iba ibb ibi ibn ibo ibr ibt iia iib iii iin iio iir iit in- ina inb ini inn ino inr int io- ioa iob ioi ion ioo ior iot ir- ira irb iri irn iro irr irt ita itb iti itn ito itt n-i naa nab nai nan nao nar nat nba nbb nbi nbn nbo nbr nbt nia nib nii nin nio nir nit nna nnb nni nnn nno nnt no- noa nob noi non noo nor not nra nrb nri nrn nro nrr nrt nta ntb nti ntn nto ntr ntt o-i oaa oab oai oan oao oar oat ob- oba obb obi obn obo obr obt oia oib oii oin oio oir oit on- ona onb oni onn ono onr ont oo- ooa oob ooi oon ooo oor oot or- ora orb ori orn oro orr ort ot- ota otb oti otn oto otr ott ra- raa rab rai ran rao rar rat rba rbb rbi rbn rbo rbr rbt ria rib rii rin rio rir rit rna rnb rni rnn rno rnr rnt roa rob roi ron roo ror rot rra rrb rri rrn rrr rrt rta rtb rti rtn rto rtr rtt taa tab tai tan tao tar tat tba tbb tbi tbn tbo tbr tbt tia tib tii tin tio tir tit tna tnb tni tnn tno tnr tnt to- toa tob toi ton too tor tot tra trb tri trn tro trr trt tta ttb tti ttn tto ttr ttt