c-- ccc cce cck ccn ccs ce- cec cee cek cen ces ckc cks cn- cnc cne cnn cns csc cse csk csn css ec- ecc ece eck ecn ecs eec eee eek een ees ekc eke eks en- enc ene enk enn ens es- esc ese esk esn ess kcc kce kck kcn kcs ke- kec kee kek ken kes kkc kke kkk kkn kks kn- knc kne knk knn ksc kse ksk ksn kss ncc nce nck ncn ncs ne- nec nee nek nen nes nkc nke nkk nkn nks nnc nne nnk nnn nns nsc nse nsk nsn nss scc sce sck scn scs se- sec see sek sen ses sk- skc ske skk sks snc sne snk snn sns ss- ssc sse ssk ssn sss