bbb bbc bbe bbk bbl bbn bcb bcc bce bck bcl bcn be- beb bec bee bek bel ben bkb bkc bke bkk bkl bkn blb blc ble blk bll bln bnb bnc bne bnk bnl bnn c-- cbb cbc cbe cbk cbl cbn ccb ccc cce cck ccl ccn ce- ceb cec cee cek cel cen ckb ckc cl- clb clc cle clk cll cln cn- cnb cnc cne cnl cnn ebb ebc ebe ebk ebl ebn ec- ecb ecc ece eck ecl ecn eeb eec eee eek eel een ekb ekc eke ekl elb elc ele elk ell eln en- enb enc ene enk enl enn kbb kbc kbe kbk kbl kbn kcb kcc kce kck kcl kcn ke- keb kec kee kek kel ken kkb kkc kke kkk kkl kkn kl- klb klc kn- knc kne knk knl knn lbb lbc lbe lbk lbl lcb lcc lce lck lcl lcn leb lec lee lek lel len lkb lkl llb llc lle llk lll lln lnb lnc lne lnk lnl lnn nbb nbc nbe nbk nbl nbn ncb ncc nce nck ncl ncn ne- neb nec nee nek nel nen nkc nke nkk nkn nlb nlc nle nlk nll nln nnb nnc nne nnk nnl nnn