c-- ccc cce ccf ccn cco ccs ce- cec cee cef cen ceo ces cfc cfe cff cfn cfo cfs cn- cnc cne cnf cnn cno cns co- coc coe cof con coo cos csc cse csf csn cso css ec- ecc ece ecf ecn eco ecs eec eee eef een eeo ees ef- efc efe eff efo efs en- enc ene enf enn eno ens eo- eoc eoe eof eon eoo eos es- esc ese esf esn eso ess fcc fce fcf fcn fco fcs fec fee fef fen feo fes ffc ffe fff ffn ffo ffs fnc fne fnf fnn fns foc foe fof fon foo fos fsc fse fsf fsn fso fss ncc nce ncf ncn nco ncs ne- nec nee nef nen neo nes nfc nfe nff nfn nfo nfs nnc nne nnf nnn nno nns no- noc noe nof non noo nos nsc nse nsf nsn nso nss oc- occ ocf ocn oco ocs oec oee oef oen oeo oes of- ofc ofe off ofn ofo ofs on- onc one onf onn ono ons oo- ooc oof oon ooo oos os- osc ose osf osn oso oss scc sce scf scn sco scs se- sec see sef sen seo ses sfc sfe sff sfn sfo sfs snc sne snf snn sno sns soc soe sof son soo sos ss- ssc sse ssf ssn sso sss