a-a a-b a-t aaa aab aan aas aat aay ab- aba abb abn abs abt aby an- ana anb ann ans ant any as- asa asb asn ass ast asy at- ata atb atn ats att ay- aya ayn ays ayt baa bab ban bas bat bay bba bbb bbn bbs bbt bby bna bnb bnn bns bnt bsa bsb bsn bss bst bsy bta btb btn bts btt bty by- bya byn bys byt naa nab nan nas nat nay nba nbb nbn nbs nbt nna nnb nnn nns nnt nsa nsb nsn nss nst nsy nta ntb ntn nts ntt nya nyn nys nyt nyy saa sab san sas sat say sba sbb sbn sbs sbt sby sna snb snn sns snt sny ss- ssa ssb ssn sss sst sta stb stn sts stt sty sy- sya syb syn sys syt taa tab tan tas tat tay tba tbb tbn tbs tbt tna tnb tnn tns tnt tsa tsb tsn tss tst tsy tta ttb ttn tts ttt tty tya tyn tys tyt yaa yab yan yas yat yay ybs yby yna ynn yns yny ysa ysb yss yst ysy yta ytn yts ytt yyb yys yyt yyy