-er a-a a-b aaa aab aae aag aao aar aau aav ab- aba abb abe abg abo abr abu abv aea aeb aee aeg aeo aer aeu aev ag- aga agb age agg ago agr agu agv aoa aob aoe aog aoo aor aou aov ar- ara arb are arg aro arr aru arv au- aua aub aue aug auo aur auv av- ava avb ave avg avo avr avu b-u baa bab bae bag bao bar bau bav bba bbb bbe bbg bbo bbr bbu be- bea beb bee beg beo ber beu bev bga bgb bge bgg bgo bgr bgu bgv boa bob boe bog boo bor bou bov bra brb bre brg bro brr bru brv bua bub bue bug buo bur buu bva bvb bve bvg bvo bvr bvu bvv eaa eab eae eag eao ear eau eav eba ebb ebe ebg ebo ebr ebu ebv eea eeb eee eeg eeo eer eev ega egb ege egg ego egr egu eo- eoa eob eoe eog eoo eor eou era erb ere erg ero err eru erv eu- eua eub eue eug eur euv eva evb eve evg evo evr evv gaa gab gae gag gao gar gau gav gba gbe gbg gbo gbr gbu gbv ge- gea geb gee geg geo ger geu gev gga ggb ggg ggo ggr ggu ggv goa gob goe gog goo gor gou gov gra grb gre grg gro grr gru grv gu- gua gub gue gug guo gur guu guv gva gvb gve gvg gvo gvr gvu oaa oab oae oag oao oar oau oav ob- oba obb obe obg obo obr obu obv oea oeb oee oeg oeo oer oga oge ogg ogo oo- ooa oob oog ooo oor oov or- ora orb ore org oro orr oru orv ou- oua oue ouo our ov- ova ovb ove ovo ovv ra- raa rab rae rag rao rar rau rav rba rbb rbe rbg rbo rbr rbu re- rea reb ree reg reo rer reu rev rga rgb rge rgg rgo rgr rgv roa rob roe rog roo ror rou rov rra rrb rrg rrr rru rua rub rue rug ruo rur ruu ruv rva rvb rve rvg rvo rvr rvu rvv ua- uaa uab uae uag uao uar uau uav uba ubb ube ubg ubo ubr ubu ubv uea ueb uee ueg uer uga ugb uge ugg ugo ugr ugu uoa uob uoe uog uoo uor ur- ura urb ure urg uro urr uru uua uue uug uur uuu uva uvb uve uvo uvu uvv v-a v-e vaa vab vae vag vao var vau vav vba vbg vbo vbr vbv vea veb vee veg veo ver veu vga vgg vgo vgr vgu voa vob voe vog voo vor vou vov vra vrb vre vrg vrr vru vue vug vur vuv vva vvb vvg vvo vvr vvv