-er b-u bbb bbe bbi bbr bbt bbu be- beb bee bei ber bet beu bi- bib bie bii bir bit biu brb bre bri brr brt bru btb bte bti btr btt btu bub bue bui bur but buu ebb ebe ebi ebr ebt ebu eeb eee eer eet eib eie eii eir eit eiu erb ere eri err ert eru etb ete eti etr ett etu eu- eub eue eui eur eut ibb ibe ibi ibr ibt ibu ie- iee iei ier iet iib iie iii iir iit iiu ir- irb ire iri irr irt iru itb ite iti itt itu iu- iub iue iui iur iut rbb rbe rbi rbr rbt rbu re- reb ree rei rer ret reu rib rie rii rir rit rrb rri rrr rrt rru rtb rte rti rtr rtt rtu rub rue rui rur rut ruu tbb tbe tbi tbr tbt tbu te- teb tee tei ter tet teu tib tie tii tir tit tiu trb tre tri trr trt tru ttb tte tti ttr ttt ttu tub tue tui tur tut tuu ubb ube ubi ubr ubt ubu ueb uee uei uer uet uib uie uii uir uit uiu ur- urb ure uri urr urt uru utb ute uti utr utt utu uue uur uut uuu

bbbb bbeb bbet bebb bebe bebi beeb beer beet beir beit bere beri berr bert beru bete beti bett betu beur bibb bibe bibi bieb bier biet bieu birb bire biri birr birt biru bite bitt bitu breb bree brei brer bret brie brit brrr brue brut btie btrt bttb bubb bube bubi bubu buer bueu buie buir buit buiu bur- burb bure buri burr burt buru but- bute buti butt ebbr eber ebit ebru ebur eeee eete eetu eiei eier eire eitb eiti eitr erbb erbe ereb erei erer eret erie erit eriu erre ertu erub erur etbr etee eter etre ette etti ettu etui eubi euer eur- eure eurt i-be ibet ibie ibri ibtb ieet ieie iere ieri iett iiie iiii iiit iitr iitt irbe iree irer iri- irie irre irri irte irti itbe iter itet itie itri itur iuiu rbbb rbbr rebb rebe rebu reeb reet reii reir reit reiu rere reri rert reru rete reti retr rett reue reut reuu rib- ribe ribu rier riet rieu rire riri rite riti ritt ritu riue rrrr rtee rtei rubb rube rubi rubu ruer ruet ruit rure ruri ruru rute ruti rutt rutu tbit tbrb tebu teer teet teie teir teiu ter- tere teri terr teru tete teti tetr tett tetu teut tibi tibu tie- tiee tiei tier tiet tiit tiiu tirb tire tiri tirr tiru tite titi titt titu tre- tree trei tret treu tri- trib trie trit trte trtr trub true trut truu ttbb tter tttt tubb tube tubr tubu tuei tuer tuet tuit tuiu turb ture turi turr turt turu tute tuti tutt tutu u-ie ubbe ubbi uber ubet ubii ubir ubit ueir uirr urbe urbi ure- uret urib urie uriu urre urri urte urur urut uter utri utti uttu uuri uuuu

-tree bbbee be-er beber bebti beebe beeri beete beeut beibi beier beire beite berbe berei beret berie berit beriu berre berri berru berte berti betee beter betie betre bett- bette betti beuer beure beute bibbe biber bibie bibri biebe biere bieri biert bieti birie birur biter bitit bitru bitte bitti biure brebu breer breet breit brere brett breu- bribe brier brite britt brrrr bruer bruet bruit bruiu bruri brute btr-t bubbe buber buire buret burie burri burru burte burtt burut buter butit butte butut ebber ebbet ebbie ebert ebibe ebure eeeee eerie eetti eirie eiter eitri erbbe erber erere erier erite eritu errtu erte erter etete etite etree etter ettie eturu eubie eurre i-bet ibbur ibert ibeti iebet ieiri ierei iette iiiee iiiii iitti irbit irete irite irrit itbit itete itire itter ittre ittti itu-r itu-t ituri ituru itutu iurie rebbe reber rebet rebit rebut reere reeti rere- reree reret rerir retee reter retie rette reuer reuet reuir reute reuti ribbi riber ribet ribie rieti ririe riuer rubbi rubee ruber rubie ruere ruete ruiru ruter rutte ruutu tbeti tbtbt tbutt teber tebet tebi- teret tereu terre terri tert- teter tetr- tetri tette ti-ti tibbi tibbu tiber tibet tibur tieit tiere tieri tieut tiree tirer tiret tirit tirru tirur titer titii titre titte titti treer treet treib treie treit trere treri trete trett treut tribe tribu trieb triei trier triet trieu trit- trite tritt trubu truer truit trute ttttt tuber tubi- tubri tueie tueit tuire tuite turbe turbi turbt turei turet turie turit turre turri turtu turut tutee tutie tutte tutti tuubi tuuei tuuri tuuru u-bit uber- ubirr uitti ureit uribe urite urter urubu uruit ururi uruti urutu uter- uteri utier utter uttur utube uturu uuuuu

b-tree bbbbbb bebite beebee beeter beiber beirut berbee berber bereet berere berrer berret berrie bertie bertre berube beruri betere betete betire betrue bettee better bettie betutu beurre bibber bibiri bibiru bieber bierut biribi birute biteit bitier bitter bittie bittur biuret breere breite brette breuer bribe- bribee briber bribir bribri brubru bruree brutii brutti bubber bububu burbet burbur bureit burier buriti burree burrer burret burrie bururi burutu butere butter buttie buttir ebbert ebr-ii ebrie eburru eebree eerier eibert erbree erebti errett ettutu euerie eurite eutere i-bere i-bete i-bure i-tree irrite ittiri iturbi r-tree rebbit rebite rebuit rebute reiber reiter reteer reteet retere retire retree retret retter rettur retube returu reueir reuere reuire reuter reutte ribber ribbet ribbie ribbit ribibe ribier rieber rieter riette rietti rititi ritter riuere rubbee rubber rubbie rubier rubite rubrie rubutu rui-be ruiter rurutu ruttee rutter rutube t-tree t-tube te-uri tebbit teebee teetee teeter teirei teitur terete teribe terrer terret terrie territ terter tertre tetete tetter tibbit tiber- tibere tiberi tibert tibeti tibiri tibrie tierer tieret tiete tietie tieute tirret tirrit titbit titibu titiri tittee titter tittie trebur treete tretee tretie trette tribit tribut triibe triter truett truite truitt tubber tubbie tuiuti turbet turbit turret turtur tururu tuteur tutter tuttut u-tube ureter