-er c-- ccc cce ccf ccn ccr ccs ccx ce- cec cee cef cen cer ces cex cfc cfe cff cfn cfr cfs cfx cn- cnc cne cnf cnn cnr cns cnx crc cre crf crn crr crs crx csc cse csf csn csr css csx cxc cxf cxr cxs cxx ec- ecc ece ecf ecn ecr ecs ecx eec eee eef een eer ees eex ef- efc efe eff efr efs efx en- enc ene enf enn enr ens erc ere erf ern err ers es- esc ese esf esn esr ess esx ex- exc exe exr exs exx fcc fce fcf fcn fcr fcs fcx fec fee fef fen fer fes fex ffc ffe fff ffn ffr ffs ffx fnc fne fnf fnn fnr fns fnx frc fre frf frn frr frs fsc fse fsf fsn fsr fss fsx fxe fxr fxs fxx ncc nce ncf ncn ncr ncs ncx ne- nec nee nef nen ner nes nex nfc nfe nff nfn nfr nfs nnc nne nnf nnn nns nrc nre nrf nrn nrr nrs nrx nsc nse nsf nsn nsr nss nsx nxc rcc rce rcf rcn rcr rcs rcx re- rec ree ref ren rer res rex rfc rfe rff rfn rfr rfs rnc rnn rnr rns rrc rrf rrn rrr rrs rsc rse rsf rsn rsr rss rsx rxr rxs scc sce scf scn scr scs scx se- sec see sef sen ser ses sex sfc sfe sff sfn sfr sfs sfx snc sne snf snn snr sns sr- src sre srf srn srr srs srx ss- ssc sse ssf ssn ssr sss ssx sxc sxn sxs xcf xcr xcx xee xen xer xes xex xfe xfn xfs xfx xnc xns xrc xrf xrx xsc xss xxx