a-a a-b aaa aab aan aas aay ab- aba abb abn abs aby an- ana anb ann ans any as- asa asb asn ass asy ay- aya ayn ays baa bab ban bas bay bba bbb bbn bbs bby bna bnb bnn bns bsa bsb bsn bss bsy by- bya byn bys naa nab nan nas nay nba nbb nbn nbs nna nnb nnn nns nsa nsb nsn nss nsy nya nyn nys nyy saa sab san sas say sba sbb sbn sbs sby sna snb snn sns sny ss- ssa ssb ssn sss sy- sya syb syn sys yaa yab yan yas yay ybs yby yna ynn yns yny ysa ysb yss ysy yyb yys yyy