roer roet rofe roff rofo roge rogg rogo roob roof roog roor root rore roro rort roru rote rotg roto rotr rott roub roue rouf rout rrrr rtbf rtee rtfb rubb rube rubu ruer ruet rufe ruff rufo ruft ruge rugg rure ruro ruru rute ruto rutt rutu tbrb tebo tebu teef teer teet teff teft tegg tego tegt tegu teor ter- tere terf tero terr teru tete teto tetr tett tetu teut tfeb tfot tobe tobo tobt tobu toee toer toet toff tofo toft tofu toge togo togr togt toof toor toot tore torf torg toro torr tort toru tote toto totr tott toug tour tout tre- tree tref treg treo tret treu trfr trge troe trog troo trot trou trte trtr trub true trug trut truu ttbb tteo tter ttff ttoe tttt tubb tube tubo tubr tubu tuer tuet tufe tuff tufo tuft tufu tugg tugu tuor turb ture turf turg turo turr turt turu tute tuto tutt tutu tuuo ubbe ubbo uber ubet ubtf ufer uffe ugeo uggo uggt ugro ugur uguu uofg uofo uor- uore urbe ure- uret urfe urff urft urge urgu uro- uroo urre urte urur urut uter utfo utor utto uttu utug uutf uuuu

-tree bbbee be-er be-ro beber bebog bebot beebe beeft beete beeut beffe befoe befog befor befur begee beget begge begob begof begor begot begto begue begur begut beofe beoff beote beour berbe bereg beret berge berob beroe beror berre berru berte berto betee beter betoo betor betou betre bett- bette betto beuer beure beute bfrog bo-bo bobet bobr bobre boege boero boeuf boeur bofet boffo boger boget bogge bogoe bogof bogor bogot bogu bogue bogur bogut booer boore boort booru borbo boree borer boret borge borgo borgu boro- boroo borot borou borre borro borut botet botou botro botte bottu bouee bouer bouet bouge boure bourg boute bouto brebu breef breer breet breg- brege bregg breo- brere breto brett breu- brobo broer broft broto broue brout brrrr bruer bruet bruff bruge brugg brute btr-t bubbe buber bufet buffe buffo buger bugge bugoo bugre buret burge burgo burgu buroo burro burru burte burtt burut buteo buter buto- butor butot butou butte butuo butut ebber ebbet eberg ebert eboue ebure eeeee ef-tu efere efetf effer effet efore efter efuru efutu egger egret eofor eorre erbbe erber erege erere ergo- ergot eroge eroor erore eroto error errtu erte erter ertug erugo etete etoro etour etree etrog etter eturu eubro euro- eurre febre feeor feere fefor fegue feoff feret ferr- ferre ferro ferte feter feto- fetor fette feuer feuge feute fogbo foggo fogou fogue foore foote fore- foreo foret forge forgo forro forte forto forur fotte fotur fouee fouet fouge fougo fourb foure fourg fouro freer freet frege frere frett freur frobe froot frore frote frugo frute fruto ftrtt fu-fu fuego fuero fugee fuger fugro fugue fugug furbo furo- furor futog futur gberg gberu gbfte geber gebet gebre gebur geebo geere geert geete gefte gegge geoff georg gerbe gerbo gerre gertt geruf getee geter getgo gette getto go-go go-oo go-to gobbe gobbo gobeo gobet gobot gofer goffe gofor goget gogro gogue goobo gooff googe goore goote goout gorbe goree gorer gorge gorgo gorre goter gotoo gotor gotto gotur gouet goufe gouge goure grebe grebo greef greer greet grefe greff grege gregg grego greot grete grett greut grftr grgur groet grofe groff groge grogg groof groot grote grott groue grouf grout grrrr grubb grube grufe gruff gruft grure gruut gtrot gtube gubbe gubbo guber gubru guere guero guoge gurge guroo gurre gurro gurur gutte o-fer o-r-b obbet obegu oberg obert obete oboro obote oboue obout obreb offer offof offre offto ofget ofoto ofour ofter ogogo ogugu oo-er ooooo orbot oreo- orere orero orfeo orfeu orfoe orfor orgue orobe orobo oroer orout orret orrgo orter ortet ortoo orube oruro orutu otego otere otero ototo otour otter ottur oture oubut ouert ouoro oure- outer outgo outof outre outro outto rebbe rebeg reber rebet rebut reefe reeft reege reere refer refet reffe reffo refut reger reget regge reggo regtt regur regut reorg rere- reree reret rerob retee reter retgo retrg retro rette retto reuer reuet reute ro-ro robbe robbo rober robo- robor robot robrt robte robur roero roffe rofor roger roget rogge rogue rooer roofe rooft rooge roore roote rooue rorbu rorer roteb roter rotge roto- rotor rotot rotte rotto roubt rouer rouet roufe rouge roure route routt rubee ruber rubof rubor ruegg ruere ruete ruffe ruffo rufo- ruger ruget rugge ruter rutog rutte ruutu tbtbt tbutt teber tebet teege tefe tegre tegur teret tereu terge tergo tergu teror terre terro tert- teruo teter tetr- tetro tette teuge teuto to-be to-go tobbe tobeg tober tobet tobog tobor tobot tobou tobre toego toeof toerr toeto tofet toffo tofor tofte toget togge togou togue toobe toore torbe toreo toret torgo torob torog torre torro torte torto tortu torue toter toto- totoe totoo totte tougu toure touro toute treer treet trefe treff treg- trego trere trete trett treut troee trofe troff troft trott troue trout trubu truer truff trugg trugo truro trute ttttt tuber tubo- tubof tubog tubou tuero tuffe tufte tugof tugou tuotu turbe turbo turbt turet turgo turot turre turro turtu turut tutee tuteo tutor tutte tutto tuuru uber- ubobo ufere ufofu uforb ugoff ugro- ugrug uouee ureo- urger urgut uroob urour urter urubu urutu utebo uter- utero utro- utror utter uttur utube uturu ututo uuuuu

b-tree bbbbbb bebeto bebout beebee beebug beefer beegee beeter before beforu befour befree befret begfor begger begoff begogo begore begoro berbee berbeo berber bereet bereft berege berere berger berour berrer berret bertre berube betere betete betrue bettee better bettor betutu beugro beurre bobber boberg bobete bobote boeber boegoe boerge boerre bofete boffet bogert bogger bogoff bogore bogoro bogote boober booboo booger booget bootee booter booue borbor boreto borfee borger borgue borogo borore bororo borte botere botero botete botoro botree botter boture boubou boueer boufee bouffe bougee bouget bougou bougre bougue bouree bourou bourre boutef bouter boutet boutob boutre boutte breefe breege breere breffo