urbs ure- ures uret urre urse urss ursu urte urts urur urus urut usbc usbe usbr usbs uscc usce uscs usee user uses uset ussb ussc usse ussr usss usst ussu ustb ustc uste usts usus utec uter utes utsc uttu uuuu

-tree bbbee bbser bbsrc bbuss bcbst bcers be-er beber bebes becue becut beebe beebs beers beest beete beets beeut berbe bercu berec beres beret berre berru berse berte berts berus besee beset besse beste bests besut betee beter betes betre betrs bett- bette betts betus beuer beure beust beute brebu brece breer brees breet brere brers brese bress brest brets brett breu- brrrr brsec bruce bruer brues bruet bruse bruss brust brute bsure btc-e btr-t btstu bubbe buber buces bucet bucsu bucur burbs burcu bures buret burrs burru burse burst burte burts burtt buruc burus burut buser buses busse bussu buste busts busur busut busuu butec buter butes butte butts butut c-bus c-tec cbers ccccc ccett cebec ceber cebes cebus ceere ceese cerbu cerc- cerce cercs cerec cerer ceres ceret cerre cerrs cerse cerss certe certs cerus cesce cescr cesse ceste cests cetes cette cetus crebe crece creer crees cresc crese cress crest crete cretu creu- creue crres cruce cruet crure cruse crust cruts csere cstcc ctree cttee cubbe cubeb cuber cubes cubub cuers curbs curce curer cures curet curre currs curse curst curts cusec cuser cusse custe cutcu cutee cuter cutes cutts ebber ebbet ebers ebert ebure ecrus ecser eeeee erbbe erber erebs erecs erect erere erest erets erres errtu erses erste ersts erte erter ertes erubs eruct eruts esbus esces escrt esect esere esser esses essse essue estce estee ester estes estet estre estur estus esure etest etete etree etres etter ettes eturu eucre eurre eurus euser rebbe rebec reber rebet rebts rebus rebut recce recet rect- recte rects recue recur recus recut reece reecs reere reese reest rere- reree reres reret resee reses reset resse reste restr rests resue resus retee reter retes retsu rette retts reuer reuet reuse reuss reute rsust rubee ruber rubes rubus rucer ruere ruers ruete rurec rusce ruses russe ruste rusts rustu ruter rutte ruutu s-bus s-tec sccbc scere scert screc scree scrub scrue scrus scter sctrs scuet scure scurr scurt scuse scut- scute scuts scutt sebbe sebes sebet secre secte sects secur secus seebe seece seere seers seese seest seesu seete serbs serce serec serer seres seret serre serse serss sert- serte serts serue serut sesce seser seses sesse seste sestu sesue setec setee seter setse sette setts settu setus setut seuer seure seuss seute srbce srbec sssrb sssss steer stees steet sterc stere sterr sters stert stesu stete stets steur strbe streb stree stret streu strrs strub struc strue strut stube stubs stuer sturb sture sturt stuse stuss stute stuue subbu suber subss subst sucr- sucre sucst suere suers suess suest suete suets sueur surer sures surre surte surtr surur surus suser suses susse susus sutee suter sutes sutte suttu tbtbt tbutt teber tebet tectb teebs teers teese teest teets terce teres teret tereu terre terrs terse tert- tesse teste tests teter tetes tetr- tetsu tette teuts treer trees treet trere tres- trese tress trest trete trets trett treus treut trsce trubs trubu truce truer trues truse truss trust trute truus tsebe tsere tsets tsrcs tsuru tsuur ttest ttttt ttusb tubbs tuber tubes tucet tuctu turbe turbt turet turre turse turss turst tursu turtu turut tutee tutte tutus tuuru u-cee uber- ubers urbes ursus urter urubu uruce urucu urutu us-sc usees users usest usses uster ustur usure usutu uter- utter uttur utube uturu uuuuu

b-tree bbbbbb bbsers becure beebee beebes beerse beerst beeste beeter berbee berber berbes bereet berere beresc berest berets berrer berres berret bersee berset bertes bertre bertus berube berust besbes besbre besert besets besser besses besset bessus bester besure betere betete betrue bettee better bettes betutu beurre beuste brbcsc brebes breere breese breest breres bresse breste brests bretcu brette bretts breuer breust brubru bruces bruree brusse bruste brutes brutus bs-tbs bubber bubbes bububu bueres buetts burbet burbur burcer burets burree burrer burret burser burses burseu bursts bursuc bursut burutu busbee busser busses busset bustec bustee buster butere butter buttes butucu bututs c-cube ceecee ceesse cercus cerete cereus certes ceruce ceruse cesser cesses cesset cestes cestus cesure creese creest creete cresce creset cresse cresst creste crests cresus cretes creuse cruces cruets cruses cruset crusts csecse cubber cubebs cubers cubert cubube cucube cucurb curber curers curest curete curets currer curret cursee curser curses cursus curter curtes curtus cuscus cusecs cusser cusses cusset custer cutcut cutest cutset cuttee cutter ebbers ebbert ebbest ebbets eberts eburru ebusus eebree eerect erbree erebus erects erestu eresus eretes errest errett erster ersure eructs escuse eseebu esetce essebt essert essess esssse essure estees esterc esters estree estres estrus estter esttes esture etcetc ettutu eusebe eutere r-tree re-use rebbec rebbes rebecs rebets rebeuc rebute rebuts recces recess recrue rectus recuer recurb recure recurs recurt recuse recuts reects reeser reeses reests rerees rescet rescue resect resees resets rester restes restte resues retece reteer retees reteet retere retest retree retret retter rettur retube returu retuse reuere reuser reuses reuter reutte rreuse rubbee rubber rubeus rubutu ruccus rurutu ruscus rusetu russer russes russet russus rustre ruttee rutter rutube screeb screes screte scrubs scruse scrute scurer scurtu scutes scutte scutus sebesu sebete sebree sebrus sebseb secess secres secret secter sectur secuer secure see-er seesee seetec sercer sercus serere serers serest sereus serre- serres serret seruse sesser sesses sessue sester sestet sestre sestus sesube setees seters settee setter settsu settur seurre seurte srubec steber stebus steere steers stere- sterer steres sterre sterte steure street stress strete strube struct struer struse strust struts strutt sttstc stubbe stubbs stuber stubes sturre sturts stutte suberb subers subset suburb succur succus sucres suebee suerte sueter suetes surbet surest surete sursee surses surtur suruc susses suster sustre susure susurr suttee sutter suture t-test t-tree t-tube tbtest tectus teebee teebus teerts teests teetee teeter tercer terces tercet terese terete terets tereus terrer terres terret terser