c-- ccc cce ccf cco ccp ccs ce- cec cee cef ceo cep ces cfc cfe cff cfo cfp cfs co- coc coe cof coo cop cos cpc cpe cpf cpo cpp cps csc cse csf cso csp css ec- ecc ece ecf eco ecs eec eee eef eeo eep ees ef- efc efe eff efo efp efs eo- eoc eoe eof eoo eop eos ep- epc epe epf epo epp eps es- esc ese esf eso esp ess fcc fce fcf fco fcp fcs fec fee fef feo fep fes ffc ffe fff ffo ffp ffs foc foe fof foo fop fos fpc fpe fpo fpp fps fsc fse fsf fso fsp fss oc- occ ocf oco ocp ocs oec oee oef oeo oep oes of- ofc ofe off ofo ofp ofs oo- ooc oof ooo oop oos op- opc ope opf opo opp ops os- osc ose osf oso osp oss p-p pcc pce pcf pco pcp pcs pec pee pef peo pep pes pfc pfe pff pfo pfp pfs poc poe pof poo pop pos ppc ppe ppf ppo ppp pps ps- psc pse psf pso psp pss scc sce scf sco scp scs se- sec see sef seo sep ses sfc sfe sff sfo sfp sfs soc soe sof soo sop sos spc spe spf spo spp sps ss- ssc sse ssf sso ssp sss