-er bbb bbc bbe bbk bbr bbt bcb bcc bce bck bcr bct be- beb bec bee bek ber bet bkb bkc bke bkk bkr bkt brb bre brk brr brt btb btc bte btk btr btt c-- cbb cbc cbe cbk cbr cbt ccb ccc cce cck ccr cct ce- ceb cec cee cek cer cet ckb ckc ckt crb crc cre crk crr crt ctb ctc cte ctk ctr ctt ebb ebc ebe ebk ebr ebt ec- ecb ecc ece eck ecr ect eeb eec eee eek eer eet ekb ekc eke ekr ekt erb erc ere erk err ert etb etc ete etk etr ett k-t kbb kbc kbe kbk kbr kcb kcc kce kck kcr kct ke- keb kec kee kek ker ket kkb kkc kke kkk kkr kkt krc krk krr krt ktb ktc kte ktk ktr ktt rbb rbc rbe rbk rbr rbt rcb rcc rce rcr rct re- reb rec ree rek rer ret rkb rkc rke rkk rkt rrb rrc rrk rrr rrt rtb rtc rte rtk rtr rtt tbb tbc tbe tbk tbr tbt tcb tcc tce tck tcr tct te- teb tec tee tek ter tet tkb tkc tke tkk tkr tkt trb trc tre trk trr trt ttb ttc tte ttk ttr ttt

bbbb bbeb bbet bbrc bcbc bccc bcec bcer bcet bctc bebb bebe beck beeb beek beer beet beke berc bere berk berr bert betc bete bett brcb brce breb brec bree brek brer bret brkb brrr brtc btcc btec btek btrc btrt bttb cbbc cbcc cbce cbcr cbct cbec cbee cber cbet cbkr cbre cbrt cbtc ccbc cccb cccc ccee ccrc ccre ccrt cctb cctc cctt cec- cece cect ceeb ceec ceke cer- cerc cere cert cet- cete ckbc ckbe ckck cker ckrc cktb crbc crcc crce crcr cre- creb crec cree cret crkc crrt crtc ctec ctrc ebbc ebbr ebcc eber ecbc ecbe eccb eccc ecce ecct ecrc ecrr ect- ectc eeee eeke eerc eetc eete ekeb ekek eker eket erbb erbe ercc erce ereb erec erer eret erke errc erre etbc etbr etcc etec etee eter etre ette kbbb kbbc kbbe kbbk kbbr kbbt kbcb kbce kbck kbcr kbct kbeb kbec kbee kbek kber kbet kbkb kbkk kbkr kbrb kbrc kbre kbrk kbrt kbtb kbtc kbte kbtk kbtr kbtt kcbc kcbk kcbr kccb kccc kcck kccr kcct kceb kcec kcee kcet kckc kckk kckr kcrc kcrr kcrt kctb kctc kcte kebb kebc kebe kebr kebt keck kecr keek keer keet kekb kekc keke ker- kerb kerc kere kerk kerr kert ket- ketc kete ketk ketr kett kkbb kkbe kkbr kkbt kkcb kkck kkcr kkct kkkk kkrb kkrc kkre kkrk kkrr kkrt kktc kktk krbb krbe krbk krbr krbt krcb krcc krce kreb krec kree krek kret krkc krke krkk krkr krrb krrc krre krrk krrr krrt krtc krtk krtr ktbb ktbc ktbr ktbt ktcc ktce ktck ktcr ktec ktee ktek ktkb ktkc ktke ktkk ktkr ktkt ktrb ktrc ktre ktrk ktrr ktrt kttc kttk kttr kttt rbbb rbbr rcbc rccb rccc rcet rctc rebb rebe rebk recc rece reck recr rect reeb reek reet reke rekt rere rert rete retr rett rrrr rtcc rtce rtee tbcb tbcc tbce tbrb tccc tctc teck tecr tect teec teek teer teet teke ter- terc tere terk terr tete tetr tett trcc tre- trec tree trek tret trtc trte trtr ttbb tter tttt

-tree b-r-k bbbee be-er bebek beber becke beebe beeke beete beker bekke berbe berck berec berek beret berk- berke berre berte betee beter betke betre bett- bette brece breck breek breer breet breke brere brett brrrr btc-e btr-t c-tec ccccc ccett cebec ceber ceere cerc- cerce cerec cerer ceret cerke cerre certe cette crebe crece creek creer creke crete ctree cttee ebber ebbet ebert ecker eecke eeeee ekker erbbe erber erect erere erkec erte erter eteke etete etree etrek etter k-t-b kebbe kebek keber kecer keere kekec kerek keret kerre ketek keter kette kreek kreke krete rebbe rebec reber rebet recce recet recke rect- recte reece reere rekke rere- reree reret retee reter rette rt-rk tbtbt teber tebet tectb teket tekke terce terek teret terre tert- teter tetr- tette treck treer treet trere trete trett ttttt

b-tree bbbbbb becker becket beebee beeker beeter bekker berbee berber bercke bereet bereke berere berker berrer berret bertre betere betete bettee better breere brekke brette ceecee cerete creeke creete creket ebbert eckert eebree eerect erbree errett etcetc k-tree kebber keeker kerber kerker kertee ketter kreker kretek r-tree rebbec rebeck reeker retece reteer reteet retere retree retret retter t-tree teebee teetee teeter tercer tercet terete terrer terret terter tertre tetete tetter tr-rec trebce trebek treck- treece treete treker tretee trette

bbbbbbb beckett beetree berbere bereket berrett bertree bk-tree bkerke brekker cerbere cerebr- cert-ee crecket crekett eerbeek ekekete erecter kee-kee kektebe krebeck kreeker reerect reteere reterre retrete rettert tec-tec terere terreer terrere tettete trecker treetee trekker trettre

bbbbbbbb bebetter berebere betterer cekerek etbetter kerkebet ketterer recetter teketeke

beckerek beebeebee etterbeek keek-keek tebe-tebe

betterbeer cerre-tree

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