-er bbb bbe bbo bbr bbt bbx be- beb bee beo ber bet bev bex bob boe boo bor bot bov box brb bre bro brr brt brv brx btb bte bto btr btt btv btx bvb bve bvo bvr bvt bvv bxb bxo bxx ebb ebe ebo ebr ebt ebv ebx eeb eee eeo eer eet eev eex eo- eob eoe eoo eor eot erb ere ero err ert erv etb ete eto etr ett etv etx evb eve evo evr evt evv ex- exe exo exr ext exx ob- obb obe obo obr obt obv obx oeb oee oeo oer oet oex oo- oob ooo oor oot oov oox or- orb ore oro orr ort orv orx ot- otb ote oto otr ott otv ov- ovb ove ovo ovv ox- oxb oxo oxt oxx rbb rbe rbo rbr rbt rbx re- reb ree reo rer ret rev rex rob roe roo ror rot rov rox rrb rrr rrt rtb rte rto rtr rtt rtv rtx rvb rve rvo rvr rvt rvv rxr t-x tbb tbe tbo tbr tbt tbv te- teb tee teo ter tet tev tex to- tob toe too tor tot tov tox trb tre tro trr trt trv trx ttb tte tto ttr ttt ttv ttx tvb tve tvo tvr tvt tvx txe txt v-e vbo vbr vbv veb vee veo ver vet vex vob voe voo vor vot vov vox vrb vre vrr vrt vtb vte vto vtr vtt vtv vtx vvb vvo vvr vvt vvv vxr vxv xbe xbr xbx xee xer xet xev xex xoo xor xot xov xox xrt xrx xtr xtv xtx xvt xxo xxv xxx

bbbb bbeb bbet bbox bebb bebe bebo beeb beer beet beo- beor beot bere bero berr bert bete beto bett betv bevo bobb bobe bobo boee boeo boer boet boob booe boor boot boox bor- bore boro borr bort botb bote boto bott bove bovo breb bree breo brer bret brev brex brob broe broo bror brot brox brrr btex btob btor btrt bttb ebbo ebbr eber eboe eboo ebor ebox ebro eeee eero eete eext eore eoto er-x erbb erbe ereb erer eret erev erob eroe eroo erre erro erve etbr etee eter etoe etox etre etro ette etto etvo ever evet evex evoe evoo evre exer exo- exor exrx exte extr o-eo obbo ober obet obex oboe obor obot obox obre obro oere oobe ooer oooo oore oort ootb orbb orbe orbo ore- oreb oreo orer orex oro- oroe oror orot orro orte orto orve orvr otee oter oto- otoe otoo otor otov otre otro otte otto ovee over ovet ovo- ovoo ovot ovre oxer oxo- oxox oxxo rbbb rbbr rebb rebe rebo reeb reet reev reot rere rero rert rete reto retr rett reve revo rexx rob- robb robe robo robt roer roet roev roob roor root roox rore roro rort rote roto rotr rott rove rovo roxo rrrr rtee rtex rtve rver rxvt tbox tbrb tebo teer teet teev teor ter- tere tero terr tete teto tetr tett tetx text tobe tobo tobt toee toer toet toor toot tore toro torr tort torv torx tote toto totr tott tove tovo tox- toxo toxt tre- tree treo tret trev trex troe troo trot trox trte trtr ttbb tteo tter ttoe tttt tver tvro tvrr tvtv txtr veer veet veor ver- verb vere vero vert vete veto vetr veve vevo vext vexx voer voet voor voot vor- vore voro vort vote voto voxx vreo vret vrot vrto vrtx vt-x vver vvob vvvv xbee xbox xeer xer- xero xert xexe xoro xote xove xoxo xtro xxxo xxxv xxxx

-tree bbbee be-er be-ro beber bebot bebox beebe beete beeve beote berbe beret berob beroe beror berre berte berto betee beter betoo betor betre bett- bette betto bever bevor bo-bo bobet bobov bobr bobre boero booer boore boort bootx borbo boree borer boret borex boro- boroo borot borov borox borre borro borve borvo botet botev botox botro botte bovee boxbe boxee boxer bre-x breer breet breo- brere breto brett bretx breve brobo broer broto brrrr btr-t e-box ebber ebbet ebert eeeee eevee eever eorre erbbe erber erere ereve eroor erore eroto error erte erter etete etext etoro etree etter evere evero everr evert evete evett eveve evoor evote exert exorb exore exort exter extre extro o-r-b obbet obert obete oboro obote obreb obrov oo-er ooooo oovoo orbot oreo- orere orero orexo orobe orobo oroer orret orter ortet ortoo orvet otere otero ototo otrov otter ottov over- overo overt ovett oxter rebbe reber rebet rebox reere reeve reorx rere- reree reret rerob retee reter retex retox retro rette retto rever revet revox rexer ro-ro robbe robbo rober robo- robor robot robrt robte roero rooer roore roote roove rorer roteb roter roto- rotor rotot rotox rotte rotto rover rtext rtrev rttov t-box t-rex tbtbt teber tebet teret terex teror terre terro tert- terve tervo teter tetex tetov tetr- tetro tette tevet tevot texor texte to-be tobbe tober tobet tobor tobot tobre toerr toeto toobe toore torbe toreo toret torob torre torro torte torto torve torxe toter totex toto- totoe totoo totte tover tovet tovex toxo- treer treet trere trete trett treve troee trott trove trovo ttttt v-bob v-bor veber vebre veere veeve verbo vereb verex verot verre verte verve vetex vette vetto veveo vever vexer vexor voere voore vorbe vorre vorte voter votre votto voxeo voxer vrbov x-box xbxrx xerbo xero- xerox xerte xetex xexex xootr xorro xotox xover xoxox xtext xtort xtree

b-tree bbbbbb bebeto bebove beebee beeter beever beevor berbee berbeo berber bereet berere berevo berovo berrer berret bertre betere betete bettee better bettor bevoor bexter bextor bobber bobete bobote bobovo bobrov boeber boerre boober booboo bootee booter borbor boreto borore bororo borovo borte botere botero botete botevo botoro botovo botree botter bovert bovver breere brette brever brevet broter brotox brotto e-text ebbert eebree eototo erbree eroto- errett etoeot ettore everex everte exeter exorte extort extro- oberto obtree obvert oerter oooooo orever ottoor overer overte