c-- ccc cce ccn ccp ccx ce- cec cee cen cep cex cn- cnc cne cnn cnp cnx cpc cpe cpn cpp cpx cxc cxp cxx ec- ecc ece ecn ecx eec eee een eep eex en- enc ene enn enp ep- epc epe epn epp epx ex- exc exe exp exx ncc nce ncn ncp ncx ne- nec nee nen nep nex nnc nne nnn nnp npc npe npn npp nxc p-p pcc pce pcn pcp pcx pec pee pen pep pex pn- pnc pne pnn pnp pnx ppc ppe ppn ppp ppx pxc pxe xcp xcx xee xen xep xex xnc xpc xpe xpn xpp xxp xxx