-er b-u bbb bbc bbd bbe bbk bbn bbr bbu bcb bcc bcd bce bck bcn bcr bcu bdb bdc bdd bde bdk bdr bdu be- beb bec bed bee bek ben ber beu bkb bkc bke bkk bkn bkr bnb bnc bnd bne bnk bnn bnr bnu brb brd bre brk brn brr bru bub buc bud bue buk bun bur buu c-- cbb cbc cbd cbe cbk cbn cbr cbu ccb ccc ccd cce cck ccn ccr ccu cdb cdc cdd cde cdk cdn cdr cdu ce- ceb cec ced cee cek cen cer ceu ckb ckc ckd cn- cnb cnc cnd cne cnn cnr cnu crb crc crd cre crk crn crr cru cub cuc cud cue cuk cun cur cuu dbb dbc dbd dbe dbk dbn dbr dbu dcb dcc dcd dce dck dcn dcr dcu ddb ddc ddd dde ddk ddn ddr ddu de- deb dec ded dee dek den der deu dkb dkc dke dkk dkr dku dnb dnc dnd dne dnk dnn dnr drb drc drd dre drk drn drr dru dub duc dud due duk dun dur ebb ebc ebd ebe ebk ebn ebr ebu ec- ecb ecc ecd ece eck ecn ecr ecu ed- edb edc edd ede edk edn edr edu eeb eec eed eee eek een eer ekb ekc ekd eke ekr eku en- enb enc end ene enk enn enr enu erb erc erd ere erk ern err eru eu- eub euc eud eue eun eur kbb kbc kbd kbe kbk kbn kbr kbu kcb kcc kcd kce kck kcn kcr kcu kdb kdc kde kdk kdr kdu ke- keb kec ked kee kek ken ker kkb kkc kke kkk kkn kkr kku kn- knc knd kne knk knn knr knu krc krd krk krn krr kru kub kuc kud kue kuk kun kur kuu nbb nbc nbd nbe nbk nbn nbr nbu ncb ncc ncd nce nck ncn ncr ncu ndb ndc ndd nde ndk ndn ndr ndu ne- neb nec ned nee nek nen ner neu nkc nke nkk nkn nkr nku nnb nnc nne nnk nnn nnu nrb nrc nrd nre nrk nrn nrr nru nub nuc nud nue nuk nun nur nuu rbb rbc rbd rbe rbk rbn rbr rbu rcb rcc rcd rce rcn rcr rcu rdb rdc rdd rde rdn rdr rdu re- reb rec red ree rek ren rer reu rkb rkc rke rkk rku rnb rnc rnd rnn rnr rnu rrb rrc rrd rrk rrn rrr rru rub ruc rud rue ruk run rur ruu ubb ubc ube ubk ubn ubr ubu ucb ucc ucd uce uck ucn ucr ucu udb udc udd ude udk udn udr udu ueb uec ued uee uen uer ukb ukc uke ukk ukn ukr uku un- unb unc und une unk unn unr unu ur- urb urc urd ure urk urn urr uru uuc uue uun uur uuu