-er b-u bbb bbc bbe bbo bbr bbt bbu bcb bcc bce bco bcr bct bcu be- beb bec bee beo ber bet beu bob boc boe boo bor bot bou brb bre bro brr brt bru btb btc bte bto btr btt btu bub buc bue buo bur but buu c-- cbb cbc cbe cbo cbr cbt cbu ccb ccc cce cco ccr cct ccu ce- ceb cec cee ceo cer cet ceu co- cob coc coe coo cor cot cou crb crc cre cro crr crt cru ctb ctc cte cto ctr ctt ctu cub cuc cue cuo cur cut cuu ebb ebc ebe ebo ebr ebt ebu ec- ecb ecc ece eco ecr ect ecu eeb eec eee eeo eer eet eo- eob eoc eoe eoo eor eot eou erb erc ere ero err ert eru etb etc ete eto etr ett etu eu- eub euc eue eur eut ob- obb obc obe obo obr obt obu oc- ocb occ oco ocr oct ocu oeb oec oee oeo oer oet oo- oob ooc ooo oor oot or- orb orc ore oro orr ort oru ot- otb otc ote oto otr ott otu ou- ouc oue ouo our out rbb rbc rbe rbo rbr rbt rbu rcb rcc rce rco rcr rct rcu re- reb rec ree reo rer ret reu rob roc roe roo ror rot rou rrb rrc rrr rrt rru rtb rtc rte rto rtr rtt rtu rub ruc rue ruo rur rut ruu tbb tbc tbe tbo tbr tbt tbu tcb tcc tce tco tcr tct tcu te- teb tec tee teo ter tet teu to- tob toc toe too tor tot tou trb trc tre tro trr trt tru ttb ttc tte tto ttr ttt ttu tub tuc tue tuo tur tut tuu ubb ubc ube ubo ubr ubt ubu ucb ucc uce uco ucr uct ucu ueb uec uee uer uet uob uoc uoe uoo uor uot ur- urb urc ure uro urr urt uru utb utc ute uto utr utt utu uuc uue uur uut uuu

bbbb bbeb bbet bbrc bcbc bccc bcec bcer bcet bcor bcru bctc bcuc bebb bebe bebo becu beeb beer beet beo- beor beot berc bere bero berr bert beru betc bete beto bett betu beur bobb bobe bobo bobu boce boco bocu boec boee boeo boer boet boob booc booe boor boot bor- bore boro borr bort boru botb bote boto bott boue bour bout brcb brce breb brec bree breo brer bret brob broc broe broo bror brot brou brrr brtc bruc brue brut btcc btec btob btor btrc btrt bttb bubb bube bubo bubu bucc buce buco bucu buer bueu bur- burb bure buro burr burt buru but- bute buto butt c-bo cbbc cbcc cbce cbcr cbct cbcu cbec cbee cber cbet cbot cbre cbrt cbtc ccbc cccb cccc cccu ccee ccob ccoc ccrc ccre ccrt cctb cctc cctt ccuc ccut cebu cec- cece ceco cect ceeb ceec ceor ceou cer- cerc cere cero cert cet- cete ceto cobb cobe cobo cobu coce coco coct cocu coob coot cor- corb corc core coro corr cort cotb cotc cote coto cott cotu coub coue cour cout crbc crbu crcc crce crcr cre- creb crec cree creo cret creu crob croc croe croo cror crot crrt crtc crub crue crut ctec ctor ctot ctrc cub- cubb cube cucc cuce cuer curb cure curo curr curt cut- cutc cute cuto cutt ebbc ebbo ebbr ebcc eber eboe eboo ebor ebro ebru ebur ecbc ecbe eccb eccc ecce ecco ecct eco- ecot ecou ecrc ecrr ecru ect- ectc ecto eeee eeoc eerc eero eetc eete eetu eore eotc eoto erbb erbe ercc erce ereb erec erer eret erob eroc eroe eroo errc erre erro ertu erub eruc erur etbc etbr etcc etco etec etee eter etoe etre etro ette etto ettu eubc euer eur- eurc eure euro eurt o-eo obbo obec ober obet oboe obor obot obre obro ocbc occc occt oce ocee ocet ocre ocro ocrr oct- octe octo ocur oec- oecc oeec oere oobe oocr ooer oooo oore oort ootb orbb orbe orbo orbu orce orco ore- oreb orec oreo orer oro- oroe oror orot orro ortc orte orto orub otee oter oto- otoe otoo otor otre otro otte otto ottu otur oucc ouer our- oure ouro ourt out- outb oute outo ouu- rbbb rbbr rcbc rcbo rccb rccc rcet rctc rebb rebe rebo rebu recc rece recr rect recu reeb reet reot reou rere rero rert reru rete reto retr rett reue reut reuu rob- robb robe robo robt robu rocc roce roco roer roet roob roor root rorc rore roro rort roru rotc rote roto rotr rott roub roue rout rrrr rtcc rtce rtee rubb rube rubu ruce ruct ruer ruet rurc rure ruro ruru rute ruto rutt rutu tbcb tbcc tbce tbrb tccc tccu tctc tebo tebu teco tecr tect teec teer teet teor ter- terc tere tero terr teru tete teto tetr tett tetu teut tobe tobo tobt tobu toce toco toee toer toet toor toot torc tore toro torr tort toru totc tote toto totr tott tour tout trcc tre- trec tree treo tret treu troc troe troo trot trou trtc trte trtr trub truc true trut truu ttbb tteo tter ttoe tttt tubb tube tubo tubr tubu tucc tuco tuer tuet tuor turb turc ture turo turr turt turu tute tuto tutt tutu tuuo ubbe ubbo uber ubet uboc ucbc ucrc ucut uocc uor- uore urbe ure- uret uro- uroo urre urte urur urut utec uter utor utto uttu uuoc uuuu

-tree bbbee be-er be-ro beber bebot becco becue becut beebe beete beeut beote beour berbe bercu berec beret berob beroe beror berre berru berte berto betee beter betoo betor betou betre bett- bette betto beuer beure beute bo-bo bobet boboc bobr bobre bocce bocet bocor boece boero boeur booce booco booer boore boort booru borbo borce borec boree borer boret boro- boroo borot borou borre borro borut botet