c-- ccc cce cck cco ccp ccs ce- cec cee cek ceo cep ces ckc cko cks co- coc coe cok coo cop cos cpc cpe cpk cpo cpp cps csc cse csk cso csp css ec- ecc ece eck eco ecs eec eee eek eeo eep ees ekc eke eko ekp eks eo- eoc eoe eok eoo eop eos ep- epc epe epo epp eps es- esc ese esk eso esp ess kcc kce kck kcp kcs ke- kec kee kek keo kep kes kkc kke kkk kkp kks koc koe kok koo kop kos kpc kpe kpk kpo kpp kps ksc kse ksk kso ksp kss oc- occ ock oco ocp ocs oec oee oeo oep oes okc oke okk oko okp oks oo- ooc ook ooo oop oos op- opc ope opk opo opp ops os- osc ose osk oso osp oss p-p pcc pce pck pco pcp pcs pec pee pek peo pep pes pkc pke pko pkp pks poc poe pok poo pop pos ppc ppe ppk ppo ppp pps ps- psc pse psk pso psp pss scc sce sck sco scp scs se- sec see sek seo sep ses sk- skc ske skk sko skp sks soc soe sok soo sop sos spc spe spk spo spp sps ss- ssc sse ssk sso ssp sss