-er bbb bbc bbe bbf bbk bbl bbn bbr bcb bcc bce bcf bck bcl bcn bcr be- beb bec bee bef bek bel ben ber bfb bfc bfe bff bfl bfn bfr bkb bkc bke bkf bkk bkl bkn bkr blb blc ble blf blk bll bln blr bnb bnc bne bnf bnk bnl bnn bnr brb bre brf brk brl brn brr c-- cbb cbc cbe cbf cbk cbl cbn cbr ccb ccc cce ccf cck ccl ccn ccr ce- ceb cec cee cef cek cel cen cer cfb cfc cfe cff cfk cfl cfn cfr ckb ckc cl- clb clc cle clf clk cll cln clr cn- cnb cnc cne cnf cnl cnn cnr crb crc cre crf crk crl crn crr ebb ebc ebe ebf ebk ebl ebn ebr ec- ecb ecc ece ecf eck ecl ecn ecr eeb eec eee eef eek eel een eer ef- efb efc efe eff efl efr ekb ekc eke ekf ekl ekr elb elc ele elf elk ell eln elr en- enb enc ene enf enk enl enn enr erb erc ere erf erk erl ern err fbb fbc fbe fbf fbk fbl fbn fbr fcb fcc fce fcf fck fcl fcn fcr feb fec fee fef fek fel fen fer ffc ffe fff ffk ffl ffn ffr fkb fkc fkf fkk fkl flb flc fle flf fll fln flr fnb fnc fne fnf fnk fnl fnn fnr frb frc fre frf frk frl frn frr kbb kbc kbe kbf kbk kbl kbn kbr kcb kcc kce kck kcl kcn kcr ke- keb kec kee kef kek kel ken ker kfc kff kkb kkc kke kkk kkl kkn kkr kl- klb klc klf klr kn- knc kne knf knk knl knn knr krc krf krk krl krn krr lbb lbc lbe lbf lbk lbl lbr lcb lcc lce lcf lck lcl lcn lcr leb lec lee lef lek lel len ler lfb lfc lfe lff lfk lfl lfn lfr lkb lkl lkr llb llc lle llf llk lll lln llr lnb lnc lne lnk lnl lnn lnr lrb lrc lrf lrk lrn lrr nbb nbc nbe nbf nbk nbl nbn nbr ncb ncc nce ncf nck ncl ncn ncr ne- neb nec nee nef nek nel nen ner nfb nfc nfe nff nfk nfl nfn nfr nkc nke nkf nkk nkn nkr nlb nlc nle nlf nlk nll nln nlr nnb nnc nne nnf nnk nnl nnn nrb nrc nre nrf nrk nrl nrn nrr rbb rbc rbe rbf rbk rbl rbn rbr rcb rcc rce rcf rcl rcn rcr re- reb rec ree ref rek rel ren rer rfb rfc rfe rff rfk rfl rfn rfr rkb rkc rke rkf rkk rlc rle rlf rll rln rlr rnb rnc rnn rnr rrb rrc rrf rrk rrl rrn rrr