-er b-p bbb bbe bbp bbr bbs bbt be- beb bee bep ber bes bet bpb bpe bpp bpr bps bpt brb bre brp brr brs brt bsb bse bsp bsr bss bst btb bte btp btr bts btt ebb ebe ebp ebr ebs ebt eeb eee eep eer ees eet ep- epb epe epp epr eps ept erb ere erp err ers ert es- esb ese esp esr ess est etb ete etp etr ets ett p-p pbb pbe pbp pbr pbs pbt peb pee pep per pes pet ppb ppe ppp ppr pps ppt prb pre prp prr prs prt ps- psb pse psp psr pss pst pt- ptb pte ptp ptr pts ptt rbb rbe rbp rbr rbs rbt re- reb ree rep rer res ret rpb rpe rpp rpr rps rpt rrb rrp rrr rrs rrt rsb rse rsp rsr rss rst rtb rte rtp rtr rts rtt sbb sbe sbp sbr sbs sbt se- seb see sep ser ses set spb spe spp spr sps spt sr- srb sre srp srr srs srt ss- ssb sse ssp ssr sss sst stb ste stp str sts stt tbb tbe tbp tbr tbs tbt te- teb tee tep ter tes tet tpb tpe tpp tpr tps tpt trb tre trp trr trs trt tsb tse tsp tsr tss tst ttb tte ttp ttr tts ttt

bbbb bbbs bbeb bbet bbpr bebb bebe beeb beep beer bees beet bere berr bers bert bes- bese bess best bete bets bett breb bree brep brer bres bret brrr brrs brsb brsr brst bseb bsee bser bses bset bspp bspr bsse bsts btbp btps btrt btss bttb ebbr ebbs eber ebes eeee eees eeps eers eese eete eets epee eper epes eppp epps eprb eprp eprs epsp epss epte erbb erbe ereb erer eres eret erpe erps erre errs erse erst erts esbs esee eser eses eset espe espp esps esse essp esst este estp estr ests etbr etee eter etes etre ette pbrs pbsp peep peer pees peet pepe peps per- pere perp perr pers pert pese pess pest pete petr pets pett pper pppp ppps ppss ppts pptt prbs pre- preb pree prep pres pret prps prrs prse prss prtp prtr psbr psbt pseb pspp pspr psps psrp psse psst psts pter rbbb rbbr rbbs rbsp rbss rbst rebb rebe rebs reeb reep rees reet repe repp repr reps rept rere rers rert rese resp ress rest rete retr rets rett rpet rpps rpts rrrr rrsp rsee rspb rsps rsre rstp rsts rtee rtes rtps rtss rttp rtts sbbs sber sbse sbsp sbst se-e se-s se-t sebe sebs sebt seeb seep seer sees seet sepe sepp sepr seps sept serb sere serp serr sers sert sese sess sest set- sete sets sett speb spee sper spes spet spps sprs spse spsp spss spst sptb sptr spts sreb sres srps srpt srsp srtp srtr ssbr ssee ssep sses sset sspe ssps sspt ssrs sssb ssss sstb sstp ssts stbs stee step ster stes stet stpp stps stre strs stss sttr tbbs tbrb tbsp tbst tbtp teer tees teet tepe tepp ter- tere terp terr ters tese tesp tess test tete tetr tets tett tper tppp tppr tprs tpte tptp tptr tre- tree tres tret trpe trpp trps trst trte trtr tses tset tsps tspt tsse tssr tsst tsts ttbb tter ttss tttt

-tree bbbee bbser be-er beber bebes beebe beebs beeps beers beest beete beets beppe berbe beres beret berre berse berte berts besee beset besse beste bests betee beter betes betre betrs bett- bette betts breer brees breet brere brers brese bress brest brets brett brrrr btr-t ebber ebbet ebers ebert eeeee eepee epees eppes epptb erbbe erber erebs erept erere erest erets erres erses erste ersts erte erter ertes esere esp-r esper espre esser esses essse estee estep ester estes estet estre etest etete etree etres etter ettes p-rep pbers pebre peeps peere peers peert peese peest peete peets pepee pepes peppe pepst pept- perer peres peret perps perre perse persp perst perte peses pesse peste pests petbe peter petes petr- petre pette petts ppers prees preps prese press prest prete pssst pssts pter- ptere pters ptprb ptpre ptprr ptprs ptprt rebbe reber rebet rebts reepe reere reese reest repet reppe repps reprt repts rere- reree reres reret resee reses reset resse reste restr rests retee reter retes rette retts rrsps sebbe sebes sebet seebe seeps seere seers seese seest seete sepet sept- septs serbs serer seres seret serpe serps serre serse serss sert- serte serts seser seses sesse seste setee seter setse sette setts speer spees speet spere sperr spert spete spets spree spres spret srprb sssrb sssss steep steer stees steet step- stepb stepe stepp steps stept stere sterr sters stert stete stets strbe strbp streb stree strep stret strrs sttep tbsps tbtbt teber tebet teebs teepe teers teese teest teets tepee tepes tepet teres teret terps terre terrs terse tert- tespe tesse teste tests teter tetes tetr- tette tppts treer trees treet trepp trept trere tres- trese tress trest trete trets trett tsebe tsere tsets ttest ttttt

b-tree bbbbbb bbsers beebee beebes beeper beerse beerst beeste beeter bepeps berbee berber berbes bereet berere berest berets berrer berres berret bersee berset bertes bertre besbes besbre besert besets besser besses besset bestep bester betere betete bettee better bettes brebes breere breese breest breres bresse breste brests brette bretts bs-tbs ebbers ebbert ebbest ebbets eberts eebree epesse erbree eretes errest errett erster espere espers essebt essert essess esssse estees esters estree estres estter esttes pberet pebees pebete peepee peeper peerer peerse peeter peetre pepper perere peress perper perpet perree perret persee perses persse perter pertre pespes pesser pester pestre peteet peters petree petrer petter pettet pppppp ppsspp preers preest presee preses preset press- presse preste prests preter pretre prette pstree r-tree rebbes rebets reeper reeser reeses reests repete repets repper rerees resees resets respet rester restes restte reteer retees reteet retere retest retree retret retter sebete sebree sebseb