c-- ccc cce ccn ccs ccx ce- cec cee cen ces cex cn- cnc cne cnn cns cnx csc cse csn css csx cxc cxs cxx ec- ecc ece ecn ecs ecx eec eee een ees eex en- enc ene enn ens es- esc ese esn ess esx ex- exc exe exs exx ncc nce ncn ncs ncx ne- nec nee nen nes nex nnc nne nnn nns nsc nse nsn nss nsx nxc scc sce scn scs scx se- sec see sen ses sex snc sne snn sns ss- ssc sse ssn sss ssx sxc sxn sxs xcx xee xen xes xex xnc xns xsc xss xxx