-er b-u bbb bbd bbe bbr bbs bbt bbu bdb bdd bde bdr bds bdt bdu be- beb bed bee ber bes bet beu brb brd bre brr brs brt bru bsb bsd bse bsr bss bst bsu btb btd bte btr bts btt btu bub bud bue bur bus but buu dbb dbd dbe dbr dbs dbt dbu ddb ddd dde ddr dds ddt ddu de- deb ded dee der des det deu drb drd dre drr drs drt dru dsb dsd dse dsr dss dst dsu dtb dtd dte dtr dts dtt dtu dub dud due dur dus dut ebb ebd ebe ebr ebs ebt ebu ed- edb edd ede edr eds edt edu eeb eed eee eer ees eet erb erd ere err ers ert eru es- esb esd ese esr ess est esu etb etd ete etr ets ett etu eu- eub eud eue eur eus eut rbb rbd rbe rbr rbs rbt rbu rdb rdd rde rdr rds rdt rdu re- reb red ree rer res ret reu rrb rrd rrr rrs rrt rru rsb rsd rse rsr rss rst rsu rtb rtd rte rtr rts rtt rtu rub rud rue rur rus rut ruu sbb sbd sbe sbr sbs sbt sbu sdb sdd sde sdr sds sdt sdu se- seb sed see ser ses set seu sr- srb srd sre srr srs srt ss- ssb ssd sse ssr sss sst ssu stb std ste str sts stt stu sub sud sue sur sus sut suu tbb tbd tbe tbr tbs tbt tbu tdb tdd tde tdr tds tdt tdu te- teb ted tee ter tes tet teu trb trd tre trr trs trt tru tsb tsd tse tsr tss tst tsu ttb ttd tte ttr tts ttt ttu tub tud tue tur tus tut tuu ubb ube ubr ubs ubt ubu udb udd ude udr uds udt udu ueb ued uee uer ues uet ur- urb urd ure urr urs urt uru usb usd use usr uss ust usu utb utd ute utr uts utt utu uue uur uus uut uuu

bbbb bbbs bbdd bbeb bbet bd-r bdes bdsd bebb bebe bede beds bedu beeb beed beer bees beet berd bere berr bers bert beru bes- bese bess best bete bets bett betu beur brds brdt breb bred bree brer bres bret brrr brrs brsb brsr brst brud brue brus brut bsbd bseb bsed bsee bser bses bset bsrd bssd bsse bsts btdt btrt btss bttb btus bubb bube bubs bubu budb budd bude buds budu buer bueu bur- burb burd bure burr burs burt buru buse buss bust busu but- bute buts butt buus dbrs dbss dbtt dbus dddd ddes ddre ddss ddts ddub debe debs debt debu dedd dede dedu deeb deed deer dees deet der- derb dere derr ders des- dese dess dest desu dete detr dets deue deur deus deut dred dree dres dret drrs drub drue drus drut druu dsdr dsrr dsst dsts dted dtss dub- dubb dube dubs dubu dudd dude duds dudu duer dues duet dure durt duru duse dust dute duts duur duut ebbr ebbs ebed eber ebes ebru ebur ebus edde edds ede- eder edes edru edss edts edur eede eedu eeee eees eers eese eete eets eetu erbb erbe erde erds ereb ered erer eres eret erre errs erse erst erts ertu erub erur erus esbs esds esdu esee eser eses eset esrd esse esst essu estd este estr ests esus etbr etds etee eter etes etre etsu ette ettu eude euer eur- eure eurt euse rbbb rbbr rbbs rbds rbsd rbss rbst rder rebb rebe rebs rebu redd rede redr reds redu reeb reed rees reet rerd rere rers rert reru rese ress rest retd rete retr rets rett reue reus reut reuu rred rrrr rsdd rsds rsee rsre rsts rstu rtdt rtee rtes rtss rtts rubb rube rubs rubu rudd rude ruds rued ruer rues ruet rurd rure rurs ruru ruse russ rust rusu rute ruts rutt rutu ruud sbbs sbds sber sbsd sbse sbst sbus sdds sder sdes sdet sdrs sdss sdsu se-d se-e se-s se-t se-u sebe sebs sebt sede seds seeb seed seer sees seet seeu serb serd sere serr sers sert seru sese sess sest set- sete sets sett seur srde sreb sres srsd srtr srub ssbr ssdd ssee sses sset ssrs sssb ssss sstb sstd ssts stbd stbs stds sted stee ster stes stet strd stre strs stru stss sttd sttr stub stud stue stur stus stut sub- subb subd subs sudd sude suds sued suee suer sues suet sueu sur- surd sure surr surs surt suru sus- susd suse suss sust susu sute sutu suus tbbs tbrb tbst tddb tdes tdse tdss tebu tedd tede teds teed teer tees teet ter- tere terr ters teru tesd tese tess test tete tetr tets tett tetu teut tre- tred tree tres tret treu trsd trst trte trtr trub trud true trus trut truu tsbd tsdb tses tset tsse tssr tsst tsts ttbb tter ttss tttt tubb tube tubr tubs tubu tude tudu tuer tues tuet turb turd ture turr turs turt turu tusd tuss tust tute tuts tutt tutu ubbe uber ubet ubud udds uder udet udsd udts uers uess urbe urbs urde urds urdu ure- ured ures uret urre urse urss ursu urte urts urur urus urut usbe usbr usbs usde usds usdt used usee user uses uset ussb usse ussr usss usst ussu ustb uste usts usus uter utes uttu uuuu

-tree b-e-d bbbee bbser bbuss bd-re bdser bdubs be-er bebed beber bebes bedde bedee beder bedes bedet bedse bedub bedue beebe beebs beede beerd beers beesd beest beete beets beeut berbe berde berdu bered beres beret berre berru berse berte berts berus besed besee beset besse beste bests besut betee beter betes betre betrs bett- bette betts betus beuer beure beust beute brebu bredd brede bredt breed breer brees breet brerd brere brers brese bress brest brets brett breu- brrrr brud- brude bruds brued bruer