a-a a-b a-t aaa aab aao aar aat aau aav ab- aba abb abo abr abt abu abv aoa aob aoo aor aot aou aov ar- ara arb aro arr art aru arv at- ata atb ato atr att atu atv au- aua aub auo aur aut auv av- ava avb avo avr avt avu b-u baa bab bao bar bat bau bav bba bbb bbo bbr bbt bbu boa bob boo bor bot bou bov bra brb bro brr brt bru brv bta btb bto btr btt btu btv bua bub buo bur but buu bva bvb bvo bvr bvt bvu bvv oaa oab oao oar oat oau oav ob- oba obb obo obr obt obu obv oo- ooa oob ooo oor oot oov or- ora orb oro orr ort oru orv ot- ota otb oto otr ott otu otv ou- oua ouo our out ov- ova ovb ovo ovv ra- raa rab rao rar rat rau rav rba rbb rbo rbr rbt rbu roa rob roo ror rot rou rov rra rrb rrr rrt rru rta rtb rto rtr rtt rtu rtv rua rub ruo rur rut ruu ruv rva rvb rvo rvr rvt rvu rvv taa tab tao tar tat tau tav tba tbb tbo tbr tbt tbu tbv to- toa tob too tor tot tou tov tra trb tro trr trt tru trv tta ttb tto ttr ttt ttu ttv tua tub tuo tur tut tuu tuv tva tvb tvo tvr tvt tvu ua- uaa uab uao uar uat uau uav uba ubb ubo ubr ubt ubu ubv uoa uob uoo uor uot ur- ura urb uro urr urt uru uta utb uto utr utt utu utv uua uur uut uuu uva uvb uvo uvu uvv v-a vaa vab vao var vat vau vav vba vbo vbr vbv voa vob voo vor vot vou vov vra vrb vrr vrt vru vta vtb vto vtr vtt vtu vtv vur vut vuv vva vvb vvo vvr vvt vvv