a-a a-b aaa aab aao aar aas aau aay ab- aba abb abo abr abs abu aby aoa aob aoo aor aos aou ar- ara arb aro arr ars aru ary as- asa asb aso asr ass asu asy au- aua aub auo aur aus ay- aya ayo ayr ays ayu b-u baa bab bao bar bas bau bay bba bbb bbo bbr bbs bbu bby boa bob boo bor bos bou boy bra brb bro brr brs bru bry bsa bsb bso bsr bss bsu bsy bua bub buo bur bus buu buy by- bya byo byr bys byu oaa oab oao oar oas oau ob- oba obb obo obr obs obu oby oo- ooa oob ooo oor oos or- ora orb oro orr ors oru ory os- osa osb oso osr oss osu ou- oua ouo our ous oya oyo oys ra- raa rab rao rar ras rau ray rba rbb rbo rbr rbs rbu roa rob roo ror ros rou roy rra rrb rrr rrs rru rsa rsb rso rsr rss rsu rua rub ruo rur rus ruu ruy ry- rya ryo ryr rys ryu ryy saa sab sao sar sas sau say sba sbb sbo sbr sbs sbu sby soa sob soo sor sos sou soy sr- sra srb sro srr srs sry ss- ssa ssb sso ssr sss ssu sua sub suo sur sus suu suy sy- sya syb syr sys syu ua- uaa uab uao uar uas uau uay uba ubb ubo ubr ubs ubu uby uoa uob uoo uor uos ur- ura urb uro urr urs uru ury usa usb uso usr uss usu uua uur uus uuu uyo uys uyu yaa yab yao yar yas yau yay ybr ybs yby yob yoo yor yos you yoy yra yro yrs yru ysa ysb yso ysr yss ysu ysy yua yuo yur yus yuu yuy yyb yys yyu yyy