-er b-u bbb bbc bbe bbk bbn bbr bbs bbu bcb bcc bce bck bcn bcr bcs bcu be- beb bec bee bek ben ber bes beu bkb bkc bke bkk bkn bkr bks bnb bnc bne bnk bnn bnr bns bnu brb bre brk brn brr brs bru bsb bsc bse bsk bsn bsr bss bsu bub buc bue buk bun bur bus buu c-- cbb cbc cbe cbk cbn cbr cbs cbu ccb ccc cce cck ccn ccr ccs ccu ce- ceb cec cee cek cen cer ces ceu ckb ckc cks cn- cnb cnc cne cnn cnr cns cnu crb crc cre crk crn crr crs cru csb csc cse csk csn csr css csu cub cuc cue cuk cun cur cus cuu ebb ebc ebe ebk ebn ebr ebs ebu ec- ecb ecc ece eck ecn ecr ecs ecu eeb eec eee eek een eer ees ekb ekc eke ekr eks eku en- enb enc ene enk enn enr ens enu erb erc ere erk ern err ers eru es- esb esc ese esk esn esr ess esu eu- eub euc eue eun eur eus kbb kbc kbe kbk kbn kbr kbs kbu kcb kcc kce kck kcn kcr kcs kcu ke- keb kec kee kek ken ker kes kkb kkc kke kkk kkn kkr kks kku kn- knc kne knk knn knr knu krc krk krn krr krs kru ksb ksc kse ksk ksn ksr kss ksu kub kuc kue kuk kun kur kus kuu nbb nbc nbe nbk nbn nbr nbs nbu ncb ncc nce nck ncn ncr ncs ncu ne- neb nec nee nek nen ner nes neu nkc nke nkk nkn nkr nks nku nnb nnc nne nnk nnn nns nnu nrb nrc nre nrk nrn nrr nrs nru nsb nsc nse nsk nsn nsr nss nsu nub nuc nue nuk nun nur nus nuu rbb rbc rbe rbk rbn rbr rbs rbu rcb rcc rce rcn rcr rcs rcu re- reb rec ree rek ren rer res reu rkb rkc rke rkk rks rku rnb rnc rnn rnr rns rnu rrb rrc rrk rrn rrr rrs rru rsb rsc rse rsk rsn rsr rss rsu rub ruc rue ruk run rur rus ruu sbb sbc sbe sbk sbn sbr sbs sbu scb scc sce sck scn scr scs scu se- seb sec see sek sen ser ses seu sk- skb skc ske skk skr sks sku snb snc sne snk snn snr sns snu sr- srb src sre srk srn srr srs ss- ssb ssc sse ssk ssn ssr sss ssu sub suc sue suk sun sur sus suu ubb ubc ube ubk ubn ubr ubs ubu ucb ucc uce uck ucn ucr ucs ucu ueb uec uee uen uer ues ukb ukc uke ukk ukn ukr uku un- unb unc une unk unn unr uns unu ur- urb urc ure urk urn urr urs uru usb usc use usk usn usr uss usu uuc uue uun uur uus uuu

-ene bbbb bbbs bbeb bbrc bcbc bcbs bccc bccs bcec bcer bces bcnu bcrs bcru bcsc bcsn bcss bcuc bebb bebe beck becs becu beeb beek been beer bees beke beks bene benk benn bens benu berc bere berk bern berr bers beru bes- bese besk bess beuk beur bner bnrr bnss brcb brce breb brec bree brek bren brer bres brkb brns brrr brrs brsb brsr bruc brue brun brus bscs bseb bsec bsee bser bses bsns bssc bsse bubb bube bubs bubu bucc buce buck bucs bucu buen buer bueu buke bukk buku bunb bune bunk bunn buns bunu bur- burb bure burk burn burr burs buru busc buse busk buss busu buus cbbc cbbs cbcc cbce cbcn cbcr cbcs cbcu cbec cbee cber cbkn cbkr cbre cbrn cbsc cbse cbsn cbus ccbc ccbn cccb cccc cccs cccu ccee ccnb ccnc ccne ccnr ccns ccnu ccrc ccre ccrs ccsn ccss ccuc ccus cebs cebu cec- cece cecs ceeb ceec cees ceke cen- cene cens cer- cerc cere cern cers cesc cese cesr cess ckbc ckbe ckck ckcs cken cker cknb cknc ckns ckrc cksb cnbc cnes cnrc cnrr cnss crbc crbu crcc crce crcr cre- creb crec cree cren cres creu crkc crne crns crss crub crue cruk crun crus cscb cscc csce cscr cscs csec csee cser csks csne csrc csrs csse cssr csur csus cub- cubb cube cubs cucc cuce cuck cucn cuek cuer cues cuk- cuke cune curb cure curn curr curs cusb cusk cuss cusu ebbc ebbr ebbs ebcc eben eber ebes ebru ebur ebus ecbc ecbe eccb eccc ecce eces ecks ecne ecrc ecrr ecru ecsc ecse ecss ecsu ecus eecs eeee eees eeke eeks eens eerc eers eese eesk ekeb ekek eken eker ekes ekne ekur enb- enbn enbr ence encs enee ener enes enke enkr ennc enne enns ennu enrs ense ensu enue enur enus erbb erbe ercc erce ereb erec eren erer eres erke erks erne erns errc erre errs erse erub eruc erur erus esbs escb esce escr escs escu esee esek esen eser eses eske esks esku esne esse essu esus eubc euer eur- eurc eure euse kbbb kbbc kbbe kbbk kbbr kbbs kbbu kbcb kbce kbck kbcr kbcs kbcu kbeb kbec kbee kbek kben kber kbes kbkb kbkk kbkr kbnn kbnr kbnu kbrb kbrc kbre kbrk kbrn kbru kbsb kbsk kbsn kbsr kbss kbsu kbub kbuc kbue kbuk kbun kbur kbus kbuu kcbc kcbk kcbr kcbs kcbu kccb kccc kcck kccr kccu kceb kcec kcee kceu kckc kckk kckn kckr kcnb kcnr kcns kcrc kcrn kcrr kcrs kcru kcsb kcsc kcse kcsn kcsr kcss kcsu kcub kcue kcuk kebb kebc kebe kebn kebr kebu keck kecr keek keen keer kees kekb kekc keke keks keku ken- kene kenk kenn kenr kens kenu ker- kerb kerc kere kerk kern kerr kers keru kesb kesc kesk kesn kesr kess keun keur keus kkbb kkbe kkbn kkbr kkbs kkcb kkck kkcn kkcr kkcs kken kkkk kknb kkne kknn kkns kknu kkrb