-er c-- ccc cce ccn ccr ccs ce- cec cee cen cer ces cn- cnc cne cnn cnr cns crc cre crn crr crs csc cse csn csr css ec- ecc ece ecn ecr ecs eec eee een eer ees en- enc ene enn enr ens erc ere ern err ers es- esc ese esn esr ess ncc nce ncn ncr ncs ne- nec nee nen ner nes nnc nne nnn nns nrc nre nrn nrr nrs nsc nse nsn nsr nss rcc rce rcn rcr rcs re- rec ree ren rer res rnc rnn rnr rns rrc rrn rrr rrs rsc rse rsn rsr rss scc sce scn scr scs se- sec see sen ser ses snc sne snn snr sns sr- src sre srn srr srs ss- ssc sse ssn ssr sss