b-u bbb bbc bbd bbe bbk bbn bbu bcb bcc bcd bce bck bcn bcu bdb bdc bdd bde bdk bdu be- beb bec bed bee bek ben beu bkb bkc bke bkk bkn bnb bnc bnd bne bnk bnn bnu bub buc bud bue buk bun buu c-- cbb cbc cbd cbe cbk cbn cbu ccb ccc ccd cce cck ccn ccu cdb cdc cdd cde cdk cdn cdu ce- ceb cec ced cee cek cen ceu ckb ckc ckd cn- cnb cnc cnd cne cnn cnu cub cuc cud cue cuk cun cuu dbb dbc dbd dbe dbk dbn dbu dcb dcc dcd dce dck dcn dcu ddb ddc ddd dde ddk ddn ddu de- deb dec ded dee dek den deu dkb dkc dke dkk dku dnb dnc dnd dne dnk dnn dub duc dud due duk dun ebb ebc ebd ebe ebk ebn ebu ec- ecb ecc ecd ece eck ecn ecu ed- edb edc edd ede edk edn edu eeb eec eed eee eek een ekb ekc ekd eke eku en- enb enc end ene enk enn enu eu- eub euc eud eue eun kbb kbc kbd kbe kbk kbn kbu kcb kcc kcd kce kck kcn kcu kdb kdc kde kdk kdu ke- keb kec ked kee kek ken kkb kkc kke kkk kkn kku kn- knc knd kne knk knn knu kub kuc kud kue kuk kun kuu nbb nbc nbd nbe nbk nbn nbu ncb ncc ncd nce nck ncn ncu ndb ndc ndd nde ndk ndn ndu ne- neb nec ned nee nek nen neu nkc nke nkk nkn nku nnb nnc nne nnk nnn nnu nub nuc nud nue nuk nun nuu ubb ubc ube ubk ubn ubu ucb ucc ucd uce uck ucn ucu udb udc udd ude udk udn udu ueb uec ued uee uen ukb ukc uke ukk ukn uku un- unb unc und une unk unn unu uuc uue uun uuu