c-- ccc cco ccp ccr ccs cct co- coc coo cop cor cos cot cpc cpo cpp cpr cps cpt crc cro crp crr crs crt csc cso csp csr css cst ctc cto ctp ctr cts ctt oc- occ oco ocp ocr ocs oct oo- ooc ooo oop oor oos oot op- opc opo opp opr ops opt or- orc oro orp orr ors ort os- osc oso osp osr oss ost ot- otc oto otp otr ots ott p-p pcc pco pcp pcr pcs pct poc poo pop por pos pot ppc ppo ppp ppr pps ppt prc pro prp prr prs prt ps- psc pso psp psr pss pst pt- ptc pto ptp ptr pts ptt rcc rco rcp rcr rcs rct roc roo rop ror ros rot rpc rpo rpp rpr rps rpt rrc rrp rrr rrs rrt rsc rso rsp rsr rss rst rtc rto rtp rtr rts rtt scc sco scp scr scs sct soc soo sop sor sos sot spc spo spp spr sps spt sr- src sro srp srr srs srt ss- ssc sso ssp ssr sss sst stc sto stp str sts stt tcc tco tcp tcr tcs tct to- toc too top tor tos tot tpc tpo tpp tpr tps tpt trc tro trp trr trs trt tsc tso tsp tsr tss tst ttc tto ttp ttr tts ttt