bbb bbc bbk bbl bbn bcb bcc bck bcl bcn bkb bkc bkk bkl bkn blb blc blk bll bln bnb bnc bnk bnl bnn c-- cbb cbc cbk cbl cbn ccb ccc cck ccl ccn ckb ckc cl- clb clc clk cll cln cn- cnb cnc cnl cnn kbb kbc kbk kbl kbn kcb kcc kck kcl kcn kkb kkc kkk kkl kkn kl- klb klc kn- knc knk knl knn lbb lbc lbk lbl lcb lcc lck lcl lcn lkb lkl llb llc llk lll lln lnb lnc lnk lnl lnn nbb nbc nbk nbl nbn ncb ncc nck ncl ncn nkc nkk nkn nlb nlc nlk nll nln nnb nnc nnk nnl nnn