a-a a-b aaa aab aao aar aau aay ab- aba abb abo abr abu aby aoa aob aoo aor aou ar- ara arb aro arr aru ary au- aua aub auo aur ay- aya ayo ayr ayu b-u baa bab bao bar bau bay bba bbb bbo bbr bbu bby boa bob boo bor bou boy bra brb bro brr bru bry bua bub buo bur buu buy by- bya byo byr byu oaa oab oao oar oau ob- oba obb obo obr obu oby oo- ooa oob ooo oor or- ora orb oro orr oru ory ou- oua ouo our oya oyo ra- raa rab rao rar rau ray rba rbb rbo rbr rbu roa rob roo ror rou roy rra rrb rrr rru rua rub ruo rur ruu ruy ry- rya ryo ryr ryu ryy ua- uaa uab uao uar uau uay uba ubb ubo ubr ubu uby uoa uob uoo uor ur- ura urb uro urr uru ury uua uur uuu uyo uyu yaa yab yao yar yau yay ybr yby yob yoo yor you yoy yra yro yru yua yuo yur yuu yuy yyb yyu yyy