-er bbb bbe bbf bbg bbk bbr bbt be- beb bee bef beg bek ber bet bfb bfe bff bfg bfr bft bgb bge bgf bgg bgk bgr bgt bkb bke bkf bkg bkk bkr bkt brb bre brf brg brk brr brt btb bte btf btg btk btr btt ebb ebe ebf ebg ebk ebr ebt eeb eee eef eeg eek eer eet ef- efb efe eff efg efr eft egb ege egf egg egr egt ekb eke ekf ekg ekr ekt erb ere erf erg erk err ert etb ete etf etg etk etr ett fbb fbe fbf fbg fbk fbr fbt feb fee fef feg fek fer fet ffe fff ffg ffk ffr fft fgb fge fgf fgg fgr fgt fkb fkf fkg fkk fkt frb fre frf frg frk frr frt ftb fte ftf ftg ftk ftr ftt gbe gbf gbg gbk gbr gbt ge- geb gee gef geg gek ger get gfb gfe gff gfk gfr gft ggb ggg ggr ggt gkb gkt grb gre grf grg grk grr grt gtb gte gtf gtg gtk gtr gtt k-t kbb kbe kbf kbk kbr ke- keb kee kef keg kek ker ket kff kfg kgb kgf kkb kke kkk kkr kkt krf krg krk krr krt ktb kte ktf ktg ktk ktr ktt rbb rbe rbf rbg rbk rbr rbt re- reb ree ref reg rek rer ret rfb rfe rff rfg rfk rfr rft rgb rge rgf rgg rgk rgr rgt rkb rke rkf rkg rkk rkt rrb rrf rrg rrk rrr rrt rtb rte rtf rtg rtk rtr rtt tbb tbe tbf tbg tbk tbr tbt te- teb tee tef teg tek ter tet tfb tfe tff tfg tfk tfr tft tgb tge tgf tgg tgk tgr tgt tkb tke tkg tkk tkr tkt trb tre trf trg trk trr trt ttb tte ttf ttg ttk ttr ttt

bbbb bbeb bbet bbrg bebb bebe beeb beef beeg beek beer beet befe beff beft begg beke bere berg berk berr bert bete bett bfgf bftt breb bree bref breg brek brer bret brkb brrr btek btrt bttb ebbr eber eeee eefe eeke eerg eete ef-g efbr efet efke eft- egbe egee eger egfr eggb egge egre egte egtk ekeb ekek eker eket erbb erbe ereb erer eret erft erg- ergg erke erre etbr etee eter etfb etfe etre ette f--k feeb feek feer feet fefe feff fege fegg feke ferb fere ferk ferr fert fete fetr fett ffee ffff ffrr fftf free fret fter gebe geek geer geet gefe geft gege gegg gerb gere gert getb gete getg getk gett gfer ggbt ggfg gggg grbr greb gree gref greg gret grrr gtbr kbbb kbbe kbbf kbbg kbbk kbbr kbbt kbeb kbee kbef kbek kber kbet kbfb kbff kbfk kbfr kbft kbgb kbge kbgg kbgr kbgt kbkb kbkf kbkg kbkk kbkr kbrb kbre kbrf kbrg kbrk kbrt kbtb kbte kbtf kbtk kbtr kbtt kebb kebe kebr kebt keef keek keer keet kefb keff kefr keft kege kegg kegk kegr kekb keke ker- kerb kere kerf kerk kerr kert ket- kete ketf ketk ketr kett kfbk kfbt kfeb kfeg kfer kffb kfff kffg kffk kfge kfgr kfkb kfre kfrg kfrr kfte kftg kftk kftt kgbb kgbr kgbt kgeb kget kgff kgfk kgft kggf kggg kggr kgrb kgre kgrg kgrk kgrr kgrt kgtf kgtk kkbb kkbe kkbg kkbr kkbt kkeg kkfg kkfr kkft kkgb kkgr kkkk kkrb kkre kkrf kkrk kkrr kkrt kktk krbb krbe krbg krbk krbr krbt kreb kree kref krek kret krfe krff krfg krft krgt krke krkk krkr krrb krre krrf krrg krrk krrr krrt krtk krtr ktbb ktbg ktbr ktbt ktee kteg ktek ktfb ktge ktgf ktgg ktgr ktkb ktke ktkk ktkr ktkt ktrb ktre ktrf ktrg ktrk ktrr ktrt kttf kttg kttk kttr kttt rbbb rbbr rebb rebe rebk reeb reef reek reet refe reff refg refr reft rege regr regt reke rekt rere rerg rert rete retr rett rfef rgbe rgtr rkkf rrrr rtbf rtee rtfb rtkg tbrb teef teek teer teet teff teft tegg tegt teke ter- tere terf terk terr tete tetr tett tfeb tkkg tre- tree tref treg trek tret trfr trge trte trtr ttbb tter ttff ttkg tttt

-tree b-r-k bbbee be-er bebek beber beebe beeft beeke beete beffe begee beget begge beker bekke berbe bereg berek beret berge berk- berke berre berte betee beter betke betre bett- bette breef breek breer breet breg- brege bregg breke brere brett brrrr btr-t ebber ebbet eberg ebert eeeee efere efetf effer effet efter egger egrek egret ekker erbbe erber erege erere erte erter eteke etete etree etrek etter febre feere feret ferr- ferre ferte feter fette freek freer freet frege freke frere frett ftrtt gbeke gberg gbfte geber gebet gebke gebre geere geert geete gefek gefte gegge gerbe gerke gerre gertt getee geter gette grebe greef greek greer greet grefe greff grege gregg grete grett grftr grrrr gtk-- k-gee k-t-b kebbe kebek keber keefe keere kefee keget kerek keret kerre ketek keter kette kreef kreek kreke krete rebbe rebeg reber rebet reefe reeft reege reere refer refet reffe reger reget regge regtt rekke rere- reree reret retee reter retrg rette rt-rk tbtbt teber tebet teege tefe tegre teket tekke terek teret terge terre tert- teter tetr- tette treer treet trefe treff treg- trere trete trett ttttt

b-tree bbbbbb beebee beefer beegee beeker beeter befree befret begger bekker berbee berber bereet bereft berege bereke berere berger berker berrer berret bertre betere betete bettee better breefe breege breere breger bregge brekke brette ebbert eebree effere effete efreet efter- egbere egbert eggert ekberg erbree errett etgert fekete ferber ferfer fergee ferrer ferret fertee fertek ferter fetter frefre frette fterer fterre gbegbe gebbet gebert geegee gegger gekker gerber gerege gerger gerret gertte getter greefe greete greffe greger gregge gregre greter grette gteter k-tree kebber keefer keeffe keeker kegger kerber kereft kerker kertee ketter krefft kregbe kreker kretek r-tree reefer reeffe reeker refeet refeff refert refete refret refter regret reteer reteet retere retree retret