-er c-- ccc cce ccp ccr ccs cct ce- cec cee cep cer ces cet cpc cpe cpp cpr cps cpt crc cre crp crr crs crt csc cse csp csr css cst ctc cte ctp ctr cts ctt ec- ecc ece ecr ecs ect eec eee eep eer ees eet ep- epc epe epp epr eps ept erc ere erp err ers ert es- esc ese esp esr ess est etc ete etp etr ets ett p-p pcc pce pcp pcr pcs pct pec pee pep per pes pet ppc ppe ppp ppr pps ppt prc pre prp prr prs prt ps- psc pse psp psr pss pst pt- ptc pte ptp ptr pts ptt rcc rce rcp rcr rcs rct re- rec ree rep rer res ret rpc rpe rpp rpr rps rpt rrc rrp rrr rrs rrt rsc rse rsp rsr rss rst rtc rte rtp rtr rts rtt scc sce scp scr scs sct se- sec see sep ser ses set spc spe spp spr sps spt sr- src sre srp srr srs srt ss- ssc sse ssp ssr sss sst stc ste stp str sts stt tcc tce tcp tcr tcs tct te- tec tee tep ter tes tet tpc tpe tpp tpr tps tpt trc tre trp trr trs trt tsc tse tsp tsr tss tst ttc tte ttp ttr tts ttt