c-- ccc ccd cco ccp ccr ccs cct cdc cdd cdo cdp cdr cds cdt co- coc cod coo cop cor cos cot cpc cpd cpo cpp cpr cps cpt crc crd cro crp crr crs crt csc csd cso csp csr css cst ctc ctd cto ctp ctr cts ctt dcc dcd dco dcp dcr dcs dct ddc ddd ddo ddp ddr dds ddt doc dod doo dop dor dos dot dpc dpd dpo dpp dpr dps dpt drc drd dro drp drr drs drt dsc dsd dso dsp dsr dss dst dtc dtd dto dtp dtr dts dtt oc- occ ocd oco ocp ocr ocs oct odc odd odo odp odr ods odt oo- ooc ood ooo oop oor oos oot op- opc opd opo opp opr ops opt or- orc ord oro orp orr ors ort os- osc osd oso osp osr oss ost ot- otc otd oto otp otr ots ott p-p pcc pcd pco pcp pcr pcs pct pdc pdd pdo pdp pdr pds pdt poc pod poo pop por pos pot ppc ppd ppo ppp ppr pps ppt prc prd pro prp prr prs prt ps- psc psd pso psp psr pss pst pt- ptc ptd pto ptp ptr pts ptt rcc rcd rco rcp rcr rcs rct rdc rdd rdo rdp rdr rds rdt roc rod roo rop ror ros rot rpc rpd rpo rpp rpr rps rpt rrc rrd rrp rrr rrs rrt rsc rsd rso rsp rsr rss rst rtc rtd rto rtp rtr rts rtt scc scd sco scp scr scs sct sdc sdd sdo sdp sdr sds sdt soc sod soo sop sor sos sot spc spd spo spp spr sps spt sr- src srd sro srp srr srs srt ss- ssc ssd sso ssp ssr sss sst stc std sto stp str sts stt tcc tcd tco tcp tcr tcs tct tdc tdd tdo tdp tdr tds tdt to- toc tod too top tor tos tot tpc tpd tpo tpp tpr tps tpt trc trd tro trp trr trs trt tsc tsd tso tsp tsr tss tst ttc ttd tto ttp ttr tts ttt