a-a a-b a-i a-t aaa aab aai aan aas aat ab- aba abb abi abn abs abt ai- aia aib aii ain ais ait an- ana anb ani ann ans ant as- asa asb asi asn ass ast at- ata atb ati atn ats att baa bab bai ban bas bat bba bbb bbi bbn bbs bbt bi- bia bib bii bin bis bit bna bnb bni bnn bns bnt bsa bsb bsi bsn bss bst bta btb bti btn bts btt ia- iaa iab iai ian ias iat iba ibb ibi ibn ibs ibt iia iib iii iin iis iit in- ina inb ini inn ins int is- isa isb isi isn iss ist ita itb iti itn its itt n-i naa nab nai nan nas nat nba nbb nbi nbn nbs nbt nia nib nii nin nis nit nna nnb nni nnn nns nnt nsa nsb nsi nsn nss nst nta ntb nti ntn nts ntt saa sab sai san sas sat sba sbb sbi sbn sbs sbt sia sib sii sin sis sit sna snb sni snn sns snt ss- ssa ssb ssi ssn sss sst sta stb sti stn sts stt taa tab tai tan tas tat tba tbb tbi tbn tbs tbt tia tib tii tin tis tit tna tnb tni tnn tns tnt tsa tsb tsi tsn tss tst tta ttb tti ttn tts ttt