-er bbb bbe bbg bbr bbt be- beb bee beg ber bet bgb bge bgg bgr bgt brb bre brg brr brt btb bte btg btr btt ebb ebe ebg ebr ebt eeb eee eeg eer eet egb ege egg egr egt erb ere erg err ert etb ete etg etr ett gbe gbg gbr gbt ge- geb gee geg ger get ggb ggg ggr ggt grb gre grg grr grt gtb gte gtg gtr gtt rbb rbe rbg rbr rbt re- reb ree reg rer ret rgb rge rgg rgr rgt rrb rrg rrr rrt rtb rte rtg rtr rtt tbb tbe tbg tbr tbt te- teb tee teg ter tet tgb tge tgg tgr tgt trb tre trg trr trt ttb tte ttg ttr ttt

bbbb bbeb bbet bbrg bebb bebe beeb beeg beer beet begg bere berg berr bert bete bett breb bree breg brer bret brrr btrt bttb ebbr eber eeee eerg eete egbe egee eger eggb egge egre egte erbb erbe ereb erer eret erg- ergg erre etbr etee eter etre ette gebe geer geet gege gegg gerb gere gert getb gete getg gett ggbt gggg grbr greb gree greg gret grrr gtbr rbbb rbbr rebb rebe reeb reet rege regr regt rere rerg rert rete retr rett rgbe rgtr rrrr rtee tbrb teer teet tegg tegt ter- tere terr tete tetr tett tre- tree treg tret trge trte trtr ttbb tter tttt

-tree bbbee be-er beber beebe beete begee beget begge berbe bereg beret berge berre berte betee beter betre bett- bette breer breet breg- brege bregg brere brett brrrr btr-t ebber ebbet eberg ebert eeeee egger egret erbbe erber erege erere erte erter etete etree etter gberg geber gebet gebre geere geert geete gegge gerbe gerre gertt getee geter gette grebe greer greet grege gregg grete grett grrrr rebbe rebeg reber rebet reege reere reger reget regge regtt rere- reree reret retee reter retrg rette tbtbt teber tebet teege tegre teret terge terre tert- teter tetr- tette treer treet treg- trere trete trett ttttt

b-tree bbbbbb beebee beegee beeter begger berbee berber bereet berege berere berger berrer berret bertre betere betete bettee better breege breere breger bregge brette ebbert eebree egbere egbert eggert erbree errett etgert gbegbe gebbet gebert geegee gegger gerber gerege gerger gerret gertte getter greete greger gregge gregre greter grette gteter r-tree regret reteer reteet retere retree retret retter t-tree teebee teetee teeter terete terrer terret terter tertre tetete tetter treete treget tretee trette

bbbbbbb beetree begreet berbere bergere bergger berrett bertree betberg bregger egeberg egrette gebette gee-gee gerbert greetee greeter gregger gregree grgeteg rebberg reeberg regreet reteere reterre retrete rettert terere tergett terreer terrere tettete trebget treetee tregerg trettre

bbbbbbbb bebetter beerberg begetter berebere bergeret betterer etbetter gerettet greegree re-beget

beebeebee eggerberg getbetter regretter tebe-tebe terbregge

bergerette betterbeer

bbbbbbbbbbbbbbb grrrrrrrrrrrrrr