a-a a-b aaa aab aad aao aas aay ab- aba abb abd abo abs aby ad- ada adb add ado ads ady aoa aob aod aoo aos as- asa asb asd aso ass asy ay- aya ayd ayo ays baa bab bad bao bas bay bba bbb bbd bbo bbs bby bda bdb bdd bdo bds bdy boa bob bod boo bos boy bsa bsb bsd bso bss bsy by- bya byd byo bys daa dab dad dao das day dba dbb dbd dbo dbs dby dda ddb ddd ddo dds ddy doa dob dod doo dos doy dsa dsb dsd dso dss dsy dy- dya dyb dyd dyo dys dyy oaa oab oad oao oas ob- oba obb obd obo obs oby oda odb odd odo ods oo- ooa oob ood ooo oos os- osa osb osd oso oss oya oyd oyo oys saa sab sad sao sas say sba sbb sbd sbo sbs sby sda sdb sdd sdo sds sdy soa sob sod soo sos soy ss- ssa ssb ssd sso sss sy- sya syb syd sys yaa yab yad yao yas yay ybs yby yda ydo yds ydy yob yod yoo yos yoy ysa ysb yso yss ysy yyb yys yyy