a-a a-b aaa aab aag aao aar aav aay ab- aba abb abg abo abr abv aby ag- aga agb agg ago agr agv agy aoa aob aog aoo aor aov ar- ara arb arg aro arr arv ary av- ava avb avg avo avr avy ay- aya ayo ayr baa bab bag bao bar bav bay bba bbb bbg bbo bbr bby bga bgb bgg bgo bgr bgv boa bob bog boo bor bov boy bra brb brg bro brr brv bry bva bvb bvg bvo bvr bvv by- bya byg byo byr gaa gab gag gao gar gav gay gba gbg gbo gbr gbv gby gga ggb ggg ggo ggr ggv goa gob gog goo gor gov goy gra grb grg gro grr grv gry gva gvb gvg gvo gvr gy- gya gyb gyo gyr oaa oab oag oao oar oav ob- oba obb obg obo obr obv oby oga ogg ogo ogy oo- ooa oob oog ooo oor oov or- ora orb org oro orr orv ory ov- ova ovb ovo ovv oya oyo ra- raa rab rag rao rar rav ray rba rbb rbg rbo rbr rga rgb rgg rgo rgr rgv roa rob rog roo ror rov roy rra rrb rrg rrr rva rvb rvg rvo rvr rvv rvy ry- rya ryg ryo ryr ryy v-a vaa vab vag vao var vav vay vba vbg vbo vbr vbv vga vgg vgo vgr voa vob vog voo vor vov voy vra vrb vrg vrr vry vva vvb vvg vvo vvr vvv vyg yaa yab yag yao yar yav yay ybg ybr yby yga ygo yob yog yoo yor yoy yra yrg yro yva yvo yvr yvy yyb yyg yyy