c-- ccc cce ccn cco ccp ccx ce- cec cee cen ceo cep cex cn- cnc cne cnn cno cnp cnx co- coc coe con coo cop cox cpc cpe cpn cpo cpp cpx cxc cxo cxp cxx ec- ecc ece ecn eco ecx eec eee een eeo eep eex en- enc ene enn eno enp eo- eoc eoe eon eoo eop ep- epc epe epn epo epp epx ex- exc exe exo exp exx ncc nce ncn nco ncp ncx ne- nec nee nen neo nep nex nnc nne nnn nno nnp no- noc noe non noo nop nox npc npe npn npo npp nxc oc- occ ocn oco ocp ocx oec oee oen oeo oep oex on- onc one onn ono onp onx oo- ooc oon ooo oop oox op- opc ope opn opo opp opx ox- oxc oxn oxo oxx p-p pcc pce pcn pco pcp pcx pec pee pen peo pep pex pn- pnc pne pnn pno pnp pnx poc poe pon poo pop pox ppc ppe ppn ppo ppp ppx pxc pxe xcp xcx xee xen xep xex xnc xno xoc xon xoo xop xox xpc xpe xpn xpo xpp xxo xxp xxx