c-- ccc cco ccp ccr ccs co- coc coo cop cor cos cpc cpo cpp cpr cps crc cro crp crr crs csc cso csp csr css oc- occ oco ocp ocr ocs oo- ooc ooo oop oor oos op- opc opo opp opr ops or- orc oro orp orr ors os- osc oso osp osr oss p-p pcc pco pcp pcr pcs poc poo pop por pos ppc ppo ppp ppr pps prc pro prp prr prs ps- psc pso psp psr pss rcc rco rcp rcr rcs roc roo rop ror ros rpc rpo rpp rpr rps rrc rrp rrr rrs rsc rso rsp rsr rss scc sco scp scr scs soc soo sop sor sos spc spo spp spr sps sr- src sro srp srr srs ss- ssc sso ssp ssr sss