-er bbb bbe bbg bbo bbr bbt be- beb bee beg beo ber bet bgb bge bgg bgo bgr bgt bob boe bog boo bor bot brb bre brg bro brr brt btb bte btg bto btr btt ebb ebe ebg ebo ebr ebt eeb eee eeg eeo eer eet egb ege egg ego egr egt eo- eob eoe eog eoo eor eot erb ere erg ero err ert etb ete etg eto etr ett gbe gbg gbo gbr gbt ge- geb gee geg geo ger get ggb ggg ggo ggr ggt gob goe gog goo gor got grb gre grg gro grr grt gtb gte gtg gto gtr gtt ob- obb obe obg obo obr obt oeb oee oeg oeo oer oet oge ogg ogo ogt oo- oob oog ooo oor oot or- orb ore org oro orr ort ot- otb ote otg oto otr ott rbb rbe rbg rbo rbr rbt re- reb ree reg reo rer ret rgb rge rgg rgo rgr rgt rob roe rog roo ror rot rrb rrg rrr rrt rtb rte rtg rto rtr rtt tbb tbe tbg tbo tbr tbt te- teb tee teg teo ter tet tgb tge tgg tgo tgr tgt to- tob toe tog too tor tot trb tre trg tro trr trt ttb tte ttg tto ttr ttt

bbbb bbeb bbet bbrg bebb bebe bebo beeb beeg beer beet begg bego beo- beor beot bere berg bero berr bert bete beto bett bobb bobe bobo boee boeo boer boet boge bogg bogo bogt boob booe boog boor boot bor- bore borg boro borr bort botb bote boto bott breb bree breg breo brer bret brob broe brog broo bror brot brrr btob btor btrt bttb ebbo ebbr eber eboe eboo ebor ebro eeee eerg eero eete egbe egee eger eggb egge eggo ego- egor egot egre egte eore eoto erbb erbe ereb erer eret erg- ergg ergo erob eroe eroo erre erro etbr etee eter etoe etre etro ette etto gbbo gebe geer geet gege gegg gego geo- geog gerb gere gero gert getb gete getg geto gett ggbt gggg gobe gobo goer gogo goog goor goot gorb gore gorg goro gorr gort gote goto gott grbr greb gree greg gret grob grog groo gror grot grrr gtbr gtoe o-eo obbo ober obet oboe obor obot obre obro oegb oere ogb ogbe ogee oger ogge ogog ogre ogro oobe ooer oooo oore oort ootb orbb orbe orbo ore- oreb oreg oreo orer orge orgo oro- oroe oror orot orro orte orto otee oter oto- otoe otog otoo otor otre otro otte otto rbbb rbbr rebb rebe rebo reeb reet rege rego regr regt reog reot rere rerg rero rert rete reto retr rett rgbe rgtr rob- robb robe robo robt roeg roer roet roge rogg rogo roob roog roor root rore roro rort rote rotg roto rotr rott rrrr rtee tbrb tebo teer teet tegg tego tegt teor ter- tere tero terr tete teto tetr tett tobe tobo tobt toee toer toet toge togo togr togt toor toot tore torg toro torr tort tote toto totr tott tre- tree treg treo tret trge troe trog troo trot trte trtr ttbb tteo tter ttoe tttt

-tree bbbee be-er be-ro beber bebog bebot beebe beete begee beget begge begob begor begot begto beote berbe bereg beret berge berob beroe beror berre berte berto betee beter betoo betor betre bett- bette betto bo-bo bobet bobr bobre boege boero boger boget bogge bogoe bogor bogot booer boore boort borbo boree borer boret borge borgo boro- boroo borot borre borro botet botro botte breer breet breg- brege bregg breo- brere breto brett brobo broer broto brrrr btr-t ebber ebbet eberg ebert eeeee egger egret eorre erbbe erber erege erere ergo- ergot eroge eroor erore eroto error erte erter etete etoro etree etrog etter gberg geber gebet gebre geebo geere geert geete gegge georg gerbe gerbo gerre gertt getee geter getgo gette getto go-go go-oo go-to gobbe gobbo gobeo gobet gobot goget gogro goobo googe goore goote gorbe goree gorer gorge gorgo gorre goter gotoo gotor gotto grebe grebo greer greet grege gregg grego greot grete grett groet groge grogg groot grote grott grrrr gtrot o-r-b obbet oberg obert obete oboro obote obreb ogogo oo-er ooooo orbot oreo- orere orero orobe orobo oroer orret orrgo orter ortet ortoo otego otere otero ototo otter rebbe rebeg reber rebet reege reere reger reget regge reggo regtt reorg rere- reree reret rerob retee reter retgo retrg retro rette retto ro-ro robbe robbo rober robo- robor robot robrt robte roero roger roget rogge rooer rooge roore roote rorer roteb roter rotge roto- rotor rotot rotte rotto tbtbt teber tebet teege tegre teret terge tergo teror terre terro tert- teter tetr- tetro tette to-be to-go tobbe tobeg tober tobet tobog tobor tobot tobre toego toerr toeto toget togge toobe toore torbe toreo toret torgo torob torog torre torro torte torto toter toto- totoe totoo totte treer treet treg- trego trere trete trett troee trott ttttt

b-tree bbbbbb bebeto beebee beegee beeter begger begogo begore begoro berbee berbeo berber bereet berege berere berger berrer berret bertre betere betete bettee better bettor bobber boberg bobete bobote boeber boegoe boerge boerre bogger bogore bogoro bogote boober booboo booger booget bootee booter borbor boreto borger borogo borore bororo borte botere botero botete botoro botree botter breege breere bregbo breger bregge brette broter brotto ebbert eebree egbere egbert eggert egoboo egrote eototo erbree eroto- errett etgert etoeot ettore gbegbe gbeogo gebbet gebert geegee geegot gegger george gerber gerege gerger gerret gertte get-go getter gobbet gobero gobert gobett gogbot gogoro goober googoo goorge gooroo gootee gorbet gorger gorget gorgor gorter gotebo gotere gotter greebo greete greger gregge gregor gregre greote greter grette gretto grobbe grogge groote grotte grotto gteter oberto obtree oeroeg oerter oooooo ortego ottoor r-tree reboot rebore rebote regort regret rerobe reroot reteer reteet reteoo retere retore retort retree retret retro- retrog retrot retter robber robert robo-g roboto rogerr rogett rogger roogoo rooter