c-- ccc cce ccl ccn ccx ce- cec cee cel cen cex cl- clc cle cll cln clx cn- cnc cne cnl cnn cnx cxc cxl cxx ec- ecc ece ecl ecn ecx eec eee eel een eex elc ele ell eln elx en- enc ene enl enn ex- exc exe exl exx lcc lce lcl lcn lcx lec lee lel len lex llc lle lll lln lnc lne lnl lnn lxc lxx ncc nce ncl ncn ncx ne- nec nee nel nen nex nlc nle nll nln nlx nnc nne nnl nnn nxc nxl xcl xcx xee xel xen xex xnc xxl xxx