c-- ccc cck cco ccp ccs ckc cko cks co- coc cok coo cop cos cpc cpk cpo cpp cps csc csk cso csp css kcc kck kcp kcs kkc kkk kkp kks koc kok koo kop kos kpc kpk kpo kpp kps ksc ksk kso ksp kss oc- occ ock oco ocp ocs okc okk oko okp oks oo- ooc ook ooo oop oos op- opc opk opo opp ops os- osc osk oso osp oss p-p pcc pck pco pcp pcs pkc pko pkp pks poc pok poo pop pos ppc ppk ppo ppp pps ps- psc psk pso psp pss scc sck sco scp scs sk- skc skk sko skp sks soc sok soo sop sos spc spk spo spp sps ss- ssc ssk sso ssp sss