a-a a-b aaa aab aan aao aar aau aav ab- aba abb abn abo abr abu abv an- ana anb ann ano anr anu anv aoa aob aon aoo aor aou aov ar- ara arb arn aro arr aru arv au- aua aub aun auo aur auv av- ava avb avn avo avr avu b-u baa bab ban bao bar bau bav bba bbb bbn bbo bbr bbu bna bnb bnn bno bnr bnu bnv boa bob bon boo bor bou bov bra brb brn bro brr bru brv bua bub bun buo bur buu bva bvb bvn bvo bvr bvu bvv naa nab nan nao nar nau nav nba nbb nbn nbo nbr nbu nbv nna nnb nnn nno nnu nnv no- noa nob non noo nor nou nov nra nrb nrn nro nrr nru nrv nua nub nun nuo nur nuu nuv nva nvb nvn nvu nvv oaa oab oan oao oar oau oav ob- oba obb obn obo obr obu obv on- ona onb onn ono onr onu oo- ooa oob oon ooo oor oov or- ora orb orn oro orr oru orv ou- oua oun ouo our ov- ova ovb ovo ovv ra- raa rab ran rao rar rau rav rba rbb rbn rbo rbr rbu rna rnb rnn rno rnr rnu rnv roa rob ron roo ror rou rov rra rrb rrn rrr rru rua rub run ruo rur ruu ruv rva rvb rvn rvo rvr rvu rvv ua- uaa uab uan uao uar uau uav uba ubb ubn ubo ubr ubu ubv un- una unb unn uno unr unu unv uoa uob uon uoo uor ur- ura urb urn uro urr uru uua uun uur uuu uva uvb uvo uvu uvv v-a vaa vab van vao var vau vav vba vbo vbr vbv vn- vna vno vnr vnu vnv voa vob von voo vor vou vov vra vrb vrn vrr vru vur vuv vva vvb vvo vvr vvv