a-a a-b aaa aab aan aao aas aay ab- aba abb abn abo abs aby an- ana anb ann ano ans any aoa aob aon aoo aos as- asa asb asn aso ass asy ay- aya ayn ayo ays baa bab ban bao bas bay bba bbb bbn bbo bbs bby bna bnb bnn bno bns boa bob bon boo bos boy bsa bsb bsn bso bss bsy by- bya byn byo bys naa nab nan nao nas nay nba nbb nbn nbo nbs nna nnb nnn nno nns no- noa nob non noo nos noy nsa nsb nsn nso nss nsy nya nyn nyo nys nyy oaa oab oan oao oas ob- oba obb obn obo obs oby on- ona onb onn ono ons ony oo- ooa oob oon ooo oos os- osa osb osn oso oss oya oyo oys saa sab san sao sas say sba sbb sbn sbo sbs sby sna snb snn sno sns sny soa sob son soo sos soy ss- ssa ssb ssn sso sss sy- sya syb syn sys yaa yab yan yao yas yay ybs yby yna ynn yns yny yob yon yoo yos yoy ysa ysb yso yss ysy yyb yys yyy