a-a a-b aaa aab aah aao aas aay ab- aba abb abh abo abs aby aha ahb ahh aho ahs ahy aoa aob aoh aoo aos as- asa asb ash aso ass asy ay- aya ayh ayo ays baa bab bah bao bas bay bba bbb bbh bbo bbs bby bha bhb bhh bho bhs boa bob boh boo bos boy bsa bsb bsh bso bss bsy by- bya byh byo bys haa hab hah hao has hay hba hbb hbh hbo hbs hby hha hhb hhh hho hhs hhy hoa hob hoh hoo hos hoy hsa hsb hsh hss hsy hy- hya hyb hyh hyo hys hyy oaa oab oah oao oas ob- oba obb obh obo obs oby oha ohh oho ohs oo- ooa oob ooh ooo oos os- osa osb osh oso oss oya oyo oys saa sab sah sao sas say sba sbb sbh sbo sbs sby sh- sha shb shh sho shs shy soa sob soh soo sos soy ss- ssa ssb ssh sso sss sy- sya syb syh sys yaa yab yah yao yas yay ybs yby yha yhs yob yoo yos yoy ysa ysb yso yss ysy yyb yys yyy