-er bbb bbe bbi bbo bbr bbt be- beb bee bei beo ber bet bi- bib bie bii bio bir bit bob boe boi boo bor bot brb bre bri bro brr brt btb bte bti bto btr btt ebb ebe ebi ebo ebr ebt eeb eee eeo eer eet eib eie eii eio eir eit eo- eob eoe eoi eoo eor eot erb ere eri ero err ert etb ete eti eto etr ett ibb ibe ibi ibo ibr ibt ie- iee iei ier iet iib iie iii iio iir iit io- iob ioe ioi ioo ior iot ir- irb ire iri iro irr irt itb ite iti ito itt o-i ob- obb obe obi obo obr obt oeb oee oei oeo oer oet oib oie oii oio oir oit oo- oob ooi ooo oor oot or- orb ore ori oro orr ort ot- otb ote oti oto otr ott rbb rbe rbi rbo rbr rbt re- reb ree rei reo rer ret rib rie rii rio rir rit rob roe roi roo ror rot rrb rri rrr rrt rtb rte rti rto rtr rtt tbb tbe tbi tbo tbr tbt te- teb tee tei teo ter tet tib tie tii tio tir tit to- tob toe toi too tor tot trb tre tri tro trr trt ttb tte tti tto ttr ttt

bbbb bbeb bbet bebb bebe bebi bebo beeb beer beet beir beit beo- beor beot bere beri bero berr bert bete beti beto bett bibb bibe bibi bibo bieb bier biet bio- bioi biot birb bire biri biro birr birt bite bito bitt bobb bobe bobi bobo boee boeo boer boet boi- boie boii boit boob booe boor boot bor- bore bori boro borr bort botb bote boti boto bott breb bree brei breo brer bret brie brio brit brob broe broo bror brot brrr btie btob btor btrt bttb ebbo ebbr eber ebit eboe eboo ebor ebro eeee eero eete eiei eier eire eitb eiti eito eitr eoir eore eori eoto erbb erbe ereb erei erer eret erie erio erit erob eroe eroi eroo erre erro etbr etee eter etio etoe etre etro ette etti etto i-be ibet ibie ibot ibri ibro ibtb ieet ieie ieio iere ieri iett iiie iiii iiio iiit iioi iioo iitr iitt iobi ioee ioii ioio ioit iooi iooo iore iori iote ioto irbe iree irer iri- irie irio irob irre irri irte irti itbe iter itet itie itoi itoo itor itri itto o-eo obbo ober obet obie obit oboe oboi obor obot obre obri obro oere oeti oier oiii oire oirt oiti oobe oobi ooer oooo oore oort ootb orbb orbe orbi orbo ore- oreb oreo orer ori- orie orio orit oro- oroe oror orot orri orro orte orto otee oter otit oto- otoe otoo otor otre otro otte otti otto rbbb rbbr rebb rebe rebo reeb reet reii reir reit reot rere reri rero rert rete reti reto retr rett rib- ribe ribo rier riet riot rire riri rite riti rito ritt rob- robb robe robi robo robt roer roet roio roir roit roob rooi roor root rore rori roro rort rote roti roto rotr rott rrrr rtee rtei tbit tbrb tebo teer teet teie teir teor ter- tere teri tero terr tete teti teto tetr tett tibi tie- tiee tiei tieo tier tiet tiit tirb tire tiri tiro tirr tite titi tito titt tobe tobi tobo tobt toee toei toer toet toie toit toor toot tore tori toro torr tort tote toti toto totr tott tre- tree trei treo tret tri- trib trie trio trit troe troi troo trot trte trtr ttbb tteo tter ttoe tttt

-tree bbbee be-er be-ro beber bebot bebti beebe beeri beete beibi beier beire beite beoir beote berbe berei beret berie berio berit berob beroe beror berre berri berte berti berto betee beter betie betio betoo betor betre bett- bette betti betto bibbe bibbo biber bibie bibio bibri biebe biere bieri biert bieti biore birie biter bitit bitte bitti bitto bo-bo bobbi bobet bobr bobre bobri boero boibe boier boire boiro boite boito booer booit boore boort borbo boree borer boret borio boro- boroo borot borre borro botet botie botro botte botti breer breet breit breo- brere breto brett bribe brier briot brite brito britt brobo broer broto brrrr btr-t ebber ebbet ebbie ebert ebibe ebrio eeeee eerie eetti eieio eirie eiter eitri eorre erbbe erber erere erier erio- erite eroor erore eroto error erte erter etete etio- etite etoro etree etter ettie i-beo i-bet i-bot ibero ibert ibeti ibibo ibore iebet ieiri ierei ieroe iette iiiee iiiii iitti iobit ioooi ioooo iorio iotit iotti irbit irete irite irobo irori irrit itbit itero itete itire itobi itter ittoo ittre ittti o-r-b obbet obeie obert obete oboro obote obreb oeiro oirot oitti oo-er oobit ooioo ooooo oorie orbit orbot orebi oreo- oreoi orere orero oribe oribi orito orobe orobo oroer orret orter ortet ortoo otere oteri otero otobi otori ototo otter ottir ottoi rebbe reber rebet rebit reere reeti reoti rere- reree reret rerir rerob retee reter retie retro rette retto ribbi riber ribet ribie ribo- ribot rieti ririe ro-ro robbe robbi robbo rober robie robo- robor robot robrt robte roero roiot roite rooer roore roote rorer roteb roter rotie roto- rotor rotot rotte rotti rotto tbeti tbtbt teber tebet tebi- teito teret teroi teror terre terri terro tert- teter tetr- tetri tetro tette ti-ti tibbi tiber tibet tibor tibro tieit tiere tieri tiero tieto tiobe tiore tiree tireo tirer tiret tirit tiro- tiroi titer titii titre titte titti to-be tobbe tober tobet tobie tobit tobor tobot tobre toeit toerr toeto toobe toore torbe toreo toret torii torio torit torob torre torri torro torte torti torto toter toti- totie toto- totoe totoo totte treer treet treib treie treit trere treri trete trett tribe trieb triei trier triet trior trit- trite trito tritt troee troie trott ttttt

b-tree bbbbbb bebeto bebite beebee beeter beiber berbee berbeo berber bereet berere berrer berret berrie bertie bertre