-er b-p bbb bbc bbe bbo bbp bbr bbt bcb bcc bce bco bcp bcr bct be- beb bec bee beo bep ber bet bob boc boe boo bop bor bot bpb bpc bpe bpo bpp bpr bpt brb bre bro brp brr brt btb btc bte bto btp btr btt c-- cbb cbc cbe cbo cbp cbr cbt ccb ccc cce cco ccp ccr cct ce- ceb cec cee ceo cep cer cet co- cob coc coe coo cop cor cot cpb cpc cpe cpo cpp cpr cpt crb crc cre cro crp crr crt ctb ctc cte cto ctp ctr ctt ebb ebc ebe ebo ebp ebr ebt ec- ecb ecc ece eco ecr ect eeb eec eee eeo eep eer eet eo- eob eoc eoe eoo eop eor eot ep- epb epc epe epo epp epr ept erb erc ere ero erp err ert etb etc ete eto etp etr ett ob- obb obc obe obo obp obr obt oc- ocb occ oco ocp ocr oct oeb oec oee oeo oep oer oet oo- oob ooc ooo oop oor oot op- opb opc ope opo opp opr opt or- orb orc ore oro orp orr ort ot- otb otc ote oto otp otr ott p-p pbb pbc pbe pbo pbp pbr pbt pcb pcc pce pco pcp pcr pct peb pec pee peo pep per pet pob poc poe poo pop por pot ppb ppc ppe ppo ppp ppr ppt prb prc pre pro prp prr prt pt- ptb ptc pte pto ptp ptr ptt rbb rbc rbe rbo rbp rbr rbt rcb rcc rce rco rcp rcr rct re- reb rec ree reo rep rer ret rob roc roe roo rop ror rot rpb rpc rpe rpo rpp rpr rpt rrb rrc rrp rrr rrt rtb rtc rte rto rtp rtr rtt tbb tbc tbe tbo tbp tbr tbt tcb tcc tce tco tcp tcr tct te- teb tec tee teo tep ter tet to- tob toc toe too top tor tot tpb tpc tpe tpo tpp tpr tpt trb trc tre tro trp trr trt ttb ttc tte tto ttp ttr ttt

bbbb bbeb bbet bbpr bbrc bcbc bcbp bccc bcec bcer bcet bcor bcpp bctc bebb bebe bebo beeb beep beer beet beo- beor beot bepo berc bere bero berr bert betc bete beto bett bobb bobe bobo boce boco boec boee boeo boep boer boet boob booc booe boop boor boot bope bopp bor- bore boro borr bort botb bote boto bott bpcp bpoe bpot bprc brcb brce breb brec bree breo brep brer bret brob broc broe broo bror brot brrr brtc btbp btcc btec btob btor btrc btrt bttb c-bo cbbc cbcc cbce cbcp cbcr cbct cbec cbee cber cbet cbot cbpc cbpp cbre cbrt cbtc ccbc cccb cccc cccp ccee ccob ccoc ccpe ccpp ccpr ccrc ccre ccrp ccrt cctb cctc cctt cebp cec- cece ceco cecp cect ceeb ceec ceop ceor cepc cepe cepo cepp cepr cept cer- cerc cere cero cerp cert cet- cete ceto cetp cobb cobe cobo coce coco cocp coct coep coob coop coot cope copo copp copr copt cor- corb corc core coro corp corr cort cotb cotc cote coto cott cpbc cpce cpeb cpep cper cpre cprt cptp cptr crbc crcc crce crcr cre- creb crec cree creo crep cret crob croc croe croo crop cror crot crpc crrt crtc crtp ctcp ctec ctep ctor ctot ctpo ctpp ctrc ctrp ebbc ebbo ebbr ebcc eber eboe eboo ebor ebpo ebro ecbc ecbe eccb eccc ecce ecco ecct eco- ecop ecot ecpp ecrc ecrr ect- ectc ecto eeee eeoc eerc eero eetc eete eore eotc eoto epcc epec epee eper epoc epor epot eppc eppo eppp eprb epro eprp epte erbb erbe ercc erce ercp ereb erec erer eret erob eroc eroe eroo erpe errc erre erro etbc etbr etcc etco etec etee eter etoe etre etro ette etto o-eo obbo obec ober obet oboe obor obot obre obro ocbc occc occt oce ocee ocet ocpp ocre ocro ocrr oct- octe octo oec- oecc oeec oere oobe oocr ooer oooo oore oort ootb ootp opec opep oper opet opo- opor oppo opto orbb orbe orbo orce orco ore- oreb orec oreo orer oro- oroe oror orot orpc orpe orro ortc orte orto otee otep oter oto- otoe otoo otor otpp otre otro otte otto pbcc pboc pcbc pccc pcce pcep pcer pcoe pcpb pcpp pcrc pcre pcte pece peco pecr pect peec peep peer peet peor pepe pepo per- perc pere pero perp perr pert pete peto petr pett pobo poce poco poer poet poop poor poot pop- popc pope popo popp popt porb porc pore poro porr port potc pote poto pott ppcc pper pppo pppp pprc pptt prbc prcc prcp pre- preb prec pree prep pret pro- prob proc proe proo prop prot prtc prtp prtr ptcc pter ptop pttc rbbb rbbr rcbc rcbo rccb rccc rcep rcet rcpo rcpt rctc rebb rebe rebo recc rece recp recr rect reeb reep reet reop reot repe repo repp repr rept rere rero rert rete reto retr rett rob- robb robe robo robt rocc roce roco roer roet roob roop roor root rope ropo rorc rore roro rort rotc rote roto rotr rott rpet rpob rpoe rrrr rtcc rtce rtee rttp tbcb tbcc tbce tbrb tbtp tccc tcep tcpo tctc tebo teco tecr tect teec teer teet teor tepe tepp ter- terc tere tero terp terr tete teto tetr tett tobe tobo tobt toce toco toee toer toet toor toot top- tope topo topp topt torc tore toro torp torr tort totc tote toto totr tott tpcp tper tppp tppr tpte tptp tptr trcc tre- trec tree treo tret troc troe troo trop trot trpc trpe trpp trtc trte trtr ttbb ttcp tteo tter ttoe ttop tttt

-tree bbbee be-er be-ro beber bebop bebot becco beebe beete beote bepop beppe beppo berbe berec beret berob beroe beror berre berte berto betee beter betoo betor