-er bbb bbe bbk bbo bbr bbt be- beb bee bek beo ber bet bev bkb bke bkk bko bkr bkt bkv bob boe bok boo bor bot bov brb bre brk bro brr brt brv btb bte btk bto btr btt btv bvb bve bvk bvo bvr bvt bvv ebb ebe ebk ebo ebr ebt ebv eeb eee eek eeo eer eet eev ekb eke eko ekr ekt ekv eo- eob eoe eok eoo eor eot erb ere erk ero err ert erv etb ete etk eto etr ett etv evb eve evo evr evt evv k-t kbb kbe kbk kbo kbr ke- keb kee kek keo ker ket kev kkb kke kkk kkr kkt kkv kob koe kok koo kor kot krk kro krr krt krv ktb kte ktk kto ktr ktt ktv kvb kvk kvo kvr kvv ob- obb obe obk obo obr obt obv oeb oee oeo oer oet okb oke okk oko okr oo- oob ook ooo oor oot oov or- orb ore ork oro orr ort orv ot- otb ote otk oto otr ott otv ov- ovb ove ovo ovv rbb rbe rbk rbo rbr rbt re- reb ree rek reo rer ret rev rkb rke rkk rko rkt rkv rob roe rok roo ror rot rov rrb rrk rrr rrt rtb rte rtk rto rtr rtt rtv rvb rve rvo rvr rvt rvv tbb tbe tbk tbo tbr tbt tbv te- teb tee tek teo ter tet tev tkb tke tkk tko tkr tkt to- tob toe tok too tor tot tov trb tre trk tro trr trt trv ttb tte ttk tto ttr ttt ttv tvb tve tvk tvo tvr tvt v-e vbk vbo vbr vbv veb vee vek veo ver vet vkb vkt vob voe vok voo vor vot vov vrb vre vrk vrr vrt vtb vte vtk vto vtr vtt vtv vvb vvo vvr vvt vvv

bbbb bbeb bbet bebb bebe bebo beeb beek beer beet beke beko beo- beok beor beot bere berk bero berr bert bete beto bett betv bevo bobb bobe bobo boee boeo boer boet boke boko boob booe book boor boot bor- bore bork boro borr bort botb bote boto bott bove bovo breb bree brek breo brer bret brev brkb brob broe brok broo bror brot brrr btek btob btor btrt bttb ebbo ebbr eber eboe eboo ebor ebro eeee eeke eero eete ekeb ekek eker eket eore eoto erbb erbe ereb erer eret erev erke erob eroe eroo erre erro erve etbr etee eter etoe etok etre etro ette etto etvo ever evet evoe evoo evre evvk kbbb kbbe kbbk kbbo kbbr kbbt kbeb kbee kbek kbeo kber kbet kbev kbkb kbkk kbko kbkr kbkv kbob kboe kbok kboo kbot kbov kbrb kbre kbrk kbro kbrt kbrv kbtb kbte kbtk kbto kbtr kbtt kbtv kbvb kbvo kbvr kebb kebe kebr kebt keek keer keet kekb keke keko keok ker- kerb kere kerk kero kerr kert kerv ket- kete ketk keto ketr kett ketv keve kevt kkbb kkbe kkbo kkbr kkbt kkkk kkob kkoo kkor kkot kkov kkrb kkre kkrk kkro kkrr kkrt kkrv kktk kktv kkvr kkvt kkvv kobb kobe kobk kobo kobr kokb koke kokk koko kokr koob kook kooo koor koot koov korb kore kork koro korr kort korv kotb kote kotk koto kotr kott kotv kove kovk kovo kovr krbb krbe krbk krbr krbt kreb kree krek kreo kret krev krke krkk krko krkr krkv krob kroe krok kroo kror krov krrb krre krrk krro krrr krrt krtk krto krtr krtv krvb krve krvk krvo krvr krvv ktbb ktbr ktbt ktee ktek ktkb ktke ktkk ktko ktkr ktkt ktob ktoe ktok ktoo ktor ktot ktrb ktre ktrk ktro ktrr ktrt ktrv kttk ktto kttr kttt kttv ktvb ktve ktvk ktvo ktvr ktvt kvbr kvbt kver kvet kvob kvoe kvok kvoo kvor kvot kvov kvre kvro kvrr kvrv kvtk kvto kvtr kvtt kvtv kvvr kvvv o-eo obbo ober obet obkb oboe obok obor obot obre obro oere oker oket okko okok okor okot okre okro okto oobe ooer oooo oore oort ootb orbb orbe orbo ore- oreb orek oreo orer orke orko oro- oroe orok oror orot orro orte orto orve orvr otee oter oto- otoe otok otoo otor otov otre otro otte otto ovee over ovet ovo- ovoo ovot ovre rbbb rbbr rebb rebe rebk rebo reeb reek reet reev reke reko rekt reot rere rero rert rete reto retr rett reve revo rob- robb robe robo robt roer roet roev roke rokk roko rokr roob rook roor root rore rork roro rort rote rotk roto rotr rott rove rovo rrrr rtee rtve rver tbrb tebo teek teer teet teev teke teok teor ter- tere terk tero terr tete teto tetr tett tobe tobo tobt toee toek toer toet toke toko took toor toot tore tork toro torr tort torv tote toto totr tott tove tovo tre- tree trek treo tret trev troe troo trot trte trtr ttbb tteo tter ttoe tttt tver tvro tvrr tvtv veer veet veke veor ver- verb vere verk vero vert vete veto vetr veve vevo vkor voer voet voke voor voot vor- vore voro vort vote voto vovk vreo vret vrot vrto vver vvob vvvv

-tree b-r-k bbbee bbook be-er be-ro bebek beber bebot beebe beeke beete beeve beker bekke bekko bekok beote berbe berek beret berk- berke berko berob beroe berok beror berre berte berto betee beter betke betoo betor betre bett- bette betto bever bevke bevor bo-bo bobek bobet bobko bobok bobov bobr bobre boeke boekt boero bokeo boker boket bokko bokok bokor bokov booer booke booko boore boort borbo boree borek borer boret borko boro- borok boroo borot borov borre borro borve borvo botet botev botok botro botte bovee breek breer breet breke breo- brere breto brett breve brobo broek broer broke brook broto brrrr btr-t ebber ebbet ebeko ebert ebook eeeee eevee eever ekeko ekker ektor ektov eorre erbbe erber erere ereve erkko eroor erore eroto error erte erter eteke