-er c-- ccc cce ccf ccr ccs ce- cec cee cef cer ces cfc cfe cff cfr cfs crc cre crf crr crs csc cse csf csr css ec- ecc ece ecf ecr ecs eec eee eef eer ees ef- efc efe eff efr efs erc ere erf err ers es- esc ese esf esr ess fcc fce fcf fcr fcs fec fee fef fer fes ffc ffe fff ffr ffs frc fre frf frr frs fsc fse fsf fsr fss rcc rce rcf rcr rcs re- rec ree ref rer res rfc rfe rff rfr rfs rrc rrf rrr rrs rsc rse rsf rsr rss scc sce scf scr scs se- sec see sef ser ses sfc sfe sff sfr sfs sr- src sre srf srr srs ss- ssc sse ssf ssr sss