c-- ccc cce ccf ccm ccn ccs ce- cec cee cef cem cen ces cfc cfe cff cfm cfn cfs cmc cme cmf cmm cmn cms cn- cnc cne cnf cnm cnn cns csc cse csf csm csn css ec- ecc ece ecf ecm ecn ecs eec eee eef eem een ees ef- efc efe eff efm efs em- emc eme emf emm emn ems en- enc ene enf enm enn ens es- esc ese esf esm esn ess fcc fce fcf fcm fcn fcs fec fee fef fem fen fes ffc ffe fff ffm ffn ffs fmc fme fmf fmm fmn fms fnc fne fnf fnm fnn fns fsc fse fsf fsm fsn fss m-f mc- mcc mce mcf mcm mcn mcs mec mee mef mem men mes mfc mfe mff mfm mfn mfs mmc mme mmf mmm mmn mms mnc mne mnf mnm mnn mns msc mse msf msm msn mss ncc nce ncf ncm ncn ncs ne- nec nee nef nem nen nes nfc nfe nff nfn nfs nmc nme nmm nmn nms nnc nne nnf nnm nnn nns nsc nse nsf nsm nsn nss scc sce scf scm scn scs se- sec see sef sem sen ses sfc sfe sff sfm sfn sfs smc sme smf smm smn sms snc sne snf snm snn sns ss- ssc sse ssf ssm ssn sss