-er a-a a-b a-t aaa aab aae aag aao aar aat aav ab- aba abb abe abg abo abr abt abv aea aeb aee aeg aeo aer aet aev ag- aga agb age agg ago agr agt agv aoa aob aoe aog aoo aor aot aov ar- ara arb are arg aro arr art arv at- ata atb ate atg ato atr att atv av- ava avb ave avg avo avr avt baa bab bae bag bao bar bat bav bba bbb bbe bbg bbo bbr bbt be- bea beb bee beg beo ber bet bev bga bgb bge bgg bgo bgr bgt bgv boa bob boe bog boo bor bot bov bra brb bre brg bro brr brt brv bta btb bte btg bto btr btt btv bva bvb bve bvg bvo bvr bvt bvv eaa eab eae eag eao ear eat eav eba ebb ebe ebg ebo ebr ebt ebv eea eeb eee eeg eeo eer eet eev ega egb ege egg ego egr egt eo- eoa eob eoe eog eoo eor eot era erb ere erg ero err ert erv eta etb ete etg eto etr ett etv eva evb eve evg evo evr evt evv gaa gab gae gag gao gar gat gav gba gbe gbg gbo gbr gbt gbv ge- gea geb gee geg geo ger get gev gga ggb ggg ggo ggr ggt ggv goa gob goe gog goo gor got gov gra grb gre grg gro grr grt grv gta gtb gte gtg gto gtr gtt gtv gva gvb gve gvg gvo gvr gvt oaa oab oae oag oao oar oat oav ob- oba obb obe obg obo obr obt obv oea oeb oee oeg oeo oer oet oga oge ogg ogo ogt oo- ooa oob oog ooo oor oot oov or- ora orb ore org oro orr ort orv ot- ota otb ote otg oto otr ott otv ov- ova ovb ove ovo ovv ra- raa rab rae rag rao rar rat rav rba rbb rbe rbg rbo rbr rbt re- rea reb ree reg reo rer ret rev rga rgb rge rgg rgo rgr rgt rgv roa rob roe rog roo ror rot rov rra rrb rrg rrr rrt rta rtb rte rtg rto rtr rtt rtv rva rvb rve rvg rvo rvr rvt rvv taa tab tae tag tao tar tat tav tba tbb tbe tbg tbo tbr tbt tbv te- tea teb tee teg teo ter tet tev tga tgb tge tgg tgo tgr tgt tgv to- toa tob toe tog too tor tot tov tra trb tre trg tro trr trt trv tta ttb tte ttg tto ttr ttt ttv tva tvb tve tvg tvo tvr tvt v-a v-e vaa vab vae vag vao var vat vav vba vbg vbo vbr vbv vea veb vee veg veo ver vet vga vgg vgo vgr vgt voa vob voe vog voo vor vot vov vra vrb vre vrg vrr vrt vta vtb vte vtg vto vtr vtt vtv vva vvb vvg vvo vvr vvt vvv