a-a a-b a-i aaa aab aai aak aao aar aau ab- aba abb abi abk abo abr abu ai- aia aib aii aik aio air aiu aka akb aki akk ako akr aku aoa aob aoi aok aoo aor aou ar- ara arb ari ark aro arr aru au- aua aub aui auk auo aur b-u baa bab bai bak bao bar bau bba bbb bbi bbk bbo bbr bbu bi- bia bib bii bik bio bir biu bka bkb bkk bko bkr boa bob boi bok boo bor bou bra brb bri brk bro brr bru bua bub bui buk buo bur buu ia- iaa iab iai iao iar iau iba ibb ibi ibk ibo ibr ibu iia iib iii iio iir iiu ika ikb iki ikk iko ikr iku io- ioa iob ioi ioo ior iou ir- ira irb iri irk iro irr iru iu- iua iub iui iur ka- kaa kab kai kak kao kar kau kba kbb kbi kbk kbo kbr kbu kia kib kii kik kio kir kiu kkb kki kkk kkr kku koa kob koi kok koo kor kou kra kri krk kro krr kru kub kui kuk kur kuu o-i oaa oab oai oak oao oar oau ob- oba obb obi obk obo obr obu oia oib oii oik oio oir oiu oka okb oki okk oko okr oku oo- ooa oob ooi ook ooo oor or- ora orb ori ork oro orr oru ou- oua oui ouk ouo our ra- raa rab rai rak rao rar rau rba rbb rbi rbk rbo rbr rbu ria rib rii rik rio rir rkb rkk rko rku roa rob roi rok roo ror rou rra rrb rri rrk rrr rru rua rub rui ruk ruo rur ruu ua- uaa uab uai uak uao uar uau uba ubb ubi ubk ubo ubr ubu uia uib uii uio uir uiu uka ukb uki ukk ukr uku uoa uob uok uoo uor ur- ura urb uri urk uro urr uru uua uur uuu