-er c-- ccc cce ccp ccr cct ce- cec cee cep cer cet cpc cpe cpp cpr cpt crc cre crp crr crt ctc cte ctp ctr ctt ec- ecc ece ecr ect eec eee eep eer eet ep- epc epe epp epr ept erc ere erp err ert etc ete etp etr ett p-p pcc pce pcp pcr pct pec pee pep per pet ppc ppe ppp ppr ppt prc pre prp prr prt pt- ptc pte ptp ptr ptt rcc rce rcp rcr rct re- rec ree rep rer ret rpc rpe rpp rpr rpt rrc rrp rrr rrt rtc rte rtp rtr rtt tcc tce tcp tcr tct te- tec tee tep ter tet tpc tpe tpp tpr tpt trc tre trp trr trt ttc tte ttp ttr ttt