-er b-p bbb bbe bbi bbo bbp bbr bbt be- beb bee bei beo bep ber bet bi- bib bie bii bio bip bir bit bob boe boi boo bop bor bot bpb bpe bpi bpo bpp bpr bpt brb bre bri bro brp brr brt btb bte bti bto btp btr btt ebb ebe ebi ebo ebp ebr ebt eeb eee eeo eep eer eet eib eie eii eio eip eir eit eo- eob eoe eoi eoo eop eor eot ep- epb epe epi epo epp epr ept erb ere eri ero erp err ert etb ete eti eto etp etr ett ibb ibe ibi ibo ibp ibr ibt ie- iee iei iep ier iet iib iie iii iio iip iir iit io- iob ioe ioi ioo iop ior iot ipb ipe ipi ipo ipp ipr ipt ir- irb ire iri iro irp irr irt itb ite iti ito itp itt o-i ob- obb obe obi obo obp obr obt oeb oee oei oeo oep oer oet oib oie oii oio oip oir oit oo- oob ooi ooo oop oor oot op- opb ope opi opo opp opr opt or- orb ore ori oro orp orr ort ot- otb ote oti oto otp otr ott p-p pbb pbe pbi pbo pbp pbr pbt peb pee pei peo pep per pet pib pie pii pio pip pir pit pob poe poi poo pop por pot ppb ppe ppi ppo ppp ppr ppt prb pre pri pro prp prr prt pt- ptb pte pti pto ptp ptr ptt rbb rbe rbi rbo rbp rbr rbt re- reb ree rei reo rep rer ret rib rie rii rio rip rir rit rob roe roi roo rop ror rot rpb rpe rpi rpo rpp rpr rpt rrb rri rrp rrr rrt rtb rte rti rto rtp rtr rtt tbb tbe tbi tbo tbp tbr tbt te- teb tee tei teo tep ter tet tib tie tii tio tip tir tit to- tob toe toi too top tor tot tpb tpe tpi tpo tpp tpr tpt trb tre tri tro trp trr trt ttb tte tti tto ttp ttr ttt

bbbb bbeb bbet bbpr bebb bebe bebi bebo beeb beep beer beet beir beit beo- beor beot bepo bere beri bero berr bert bete beti beto bett bibb bibe bibi bibo bieb bier biet bio- bioi biot bipp birb bire biri biro birr birt bite bito bitt bobb bobe bobi bobo boee boeo boep boer boet boi- boie boii boit boob booe boop boor boot bope bopp bor- bore bori boro borr bort botb bote boti boto bott bpoe bpot bpti breb bree brei breo brep brer bret brie brio brit brob broe broo bror brot brrr btbp btie btob btor btrt bttb ebbo ebbr eber ebit eboe eboo ebor ebpo ebro eeee eero eete eiei eier eipo eipr eire eitb eiti eito eitr eoir eore eori eoto epee eper epi- epie epip epit epor epot eppo eppp eprb epro eprp epte erbb erbe ereb erei erer eret erie erio erit erob eroe eroi eroo erpe erre erro etbr etee eter etio etoe etre etro ette etti etto i-be ibet ibie ibot ibri ibro ibtb ieet ieie ieio iere ieri iett iiie iiii iiio iiit iioi iioo iiop iitr iitt iobi ioee ioii ioio ioit iooi iooo iore iori iote ioto iper ipet ipie ipoe ipop ippo ippr ipri ipto irbe irbp iree irer iri- irie irio irip irob irop irpe irre irri irte irti irtp itbe itep iter itet itie itoi itoo itor itri itto o-eo obbo ober obet obie obit oboe oboi obor obot obre obri obro oere oeti oier oiii oire oirt oiti oobe oobi ooer oooo oore oort ootb ootp opei opep oper opet opie opii opio opit opo- opor oppi oppo opti opto orbb orbe orbi orbo ore- oreb oreo orer ori- orie orio orit oro- oroe oror orot orpe orpi orri orro orte orto otee otep oter otit oto- otoe otoo otor otpp otre otro otte otti otto peep peer peet peio peip peir peit peor pepe pepi pepo per- pere peri pero perp perr pert pete peti peto petr pett pibb pibi piep pier piet piip piob piot pipe pipi pipo pipp pire piri piro pirr pite piti pito pitr pitt pobo poer poet poio poop poor poot pop- pope popi popo popp popt porb pore pori poro porr port pote poti poto pott pper ppib ppie pppo pppp pptt pre- preb pree prep pret pri- prie prii pro- prob proe proo prop prot prri prti prtp prtr pter ptop rbbb rbbr rebb rebe rebo reeb reep reet reii reir reit reop reot repe repi repo repp repr rept rere reri rero rert rete reti reto retr rett rib- ribe ribo riep rier riet riot ripe ripi ripp ripr ript rire riri rite riti rito ritt rob- robb robe robi robo robt roer roet roio roir roit roob rooi roop roor root rope ropo rore rori roro rort rote roti roto rotr rott rpet rpii rpob rpoe rrrr rtee rtei rttp tbit tbrb tbtp tebo teer teet teie teip teir teor tepe tepi tepp ter- tere teri tero terp terr tete teti teto tetr tett tibi tie- tiee tiei tieo tiep tier tiet tiit tiop tip- tipe tipi tipo tipp tipt tirb tire tiri tiro tirr tite titi tito titp titt tobe tobi tobo tobt toee toei toer toet toie toit toor toot top- tope topi topo topp topt tore tori toro torp torr tort tote toti toto totr tott tper tpir tppp tppr tpte tptp tptr tre- tree trei treo tret tri- trib trie trio trip trit troe troi troo trop trot trpe trpp trte trtr ttbb tteo tter ttoe ttop tttt

-tree bbbee be-er be-ro beber bebop bebot bebti beebe beepi beeri beete beibi beier beire beite beoir beote bepop beppe beppo berbe berei beret berie berio berit berob beroe beror berre berri berte berti berto betee beter betie betio betoo betor betre bett- bette