a-a a-b aaa aab aad aak aao aas aay ab- aba abb abd abk abo abs aby ad- ada adb add adk ado ads ady aka akb akd akk ako aks aoa aob aod aok aoo aos as- asa asb asd ask aso ass asy ay- aya ayd ayk ayo ays baa bab bad bak bao bas bay bba bbb bbd bbk bbo bbs bby bda bdb bdd bdk bdo bds bdy bka bkb bkk bko bks boa bob bod bok boo bos boy bsa bsb bsd bsk bso bss bsy by- bya byd byk byo bys daa dab dad dak dao das day dba dbb dbd dbk dbo dbs dby dda ddb ddd ddk ddo dds ddy dka dkb dkk dko dks doa dob dod dok doo dos doy dsa dsb dsd dsk dso dss dsy dy- dya dyb dyd dyk dyo dys dyy ka- kaa kab kad kak kao kas kay kba kbb kbd kbk kbo kbs kda kdb kdk kdo kds kdy kkb kkk kks kky koa kob kod kok koo kos koy ksa ksb ksd ksk kso kss kya kyd kyo kys oaa oab oad oak oao oas ob- oba obb obd obk obo obs oby oda odb odd odo ods oka okb okd okk oko oks oo- ooa oob ood ook ooo oos os- osa osb osd osk oso oss oya oyd oyo oys saa sab sad sak sao sas say sba sbb sbd sbk sbo sbs sby sda sdb sdd sdk sdo sds sdy sk- ska skb skd skk sko sks sky soa sob sod sok soo sos soy ss- ssa ssb ssd ssk sso sss sy- sya syb syd syk sys yaa yab yad yak yao yas yay ybs yby yda ydo yds ydy yka ykk yob yod yok yoo yos yoy ysa ysb ysk yso yss ysy yyb yys yyy