-er c-- ccc cce ccp ccr ccs cct ccx ce- cec cee cep cer ces cet cex cpc cpe cpp cpr cps cpt cpx crc cre crp crr crs crt crx csc cse csp csr css cst csx ctc cte ctp ctr cts ctt ctx cxc cxp cxr cxs cxt cxx ec- ecc ece ecr ecs ect ecx eec eee eep eer ees eet eex ep- epc epe epp epr eps ept epx erc ere erp err ers ert es- esc ese esp esr ess est esx etc ete etp etr ets ett etx ex- exc exe exp exr exs ext exx p-p pcc pce pcp pcr pcs pct pcx pec pee pep per pes pet pex ppc ppe ppp ppr pps ppt ppx prc pre prp prr prs prt prx ps- psc pse psp psr pss pst psx pt- ptc pte ptp ptr pts ptt ptx pxc pxe pxr pxs pxt rcc rce rcp rcr rcs rct rcx re- rec ree rep rer res ret rex rpc rpe rpp rpr rps rpt rpx rrc rrp rrr rrs rrt rsc rse rsp rsr rss rst rsx rtc rte rtp rtr rts rtt rtx rxp rxr rxs scc sce scp scr scs sct scx se- sec see sep ser ses set sex spc spe spp spr sps spt spx sr- src sre srp srr srs srt srx ss- ssc sse ssp ssr sss sst ssx stc ste stp str sts stt stx sxc sxs sxt t-x tcc tce tcp tcr tcs tct tcx te- tec tee tep ter tes tet tex tpc tpe tpp tpr tps tpt tpx trc tre trp trr trs trt trx tsc tse tsp tsr tss tst tsx ttc tte ttp ttr tts ttt ttx txe txs txt xcp xcr xcx xee xep xer xes xet xex xpc xpe xpp xps xpt xrc xrt xrx xsc xsp xss xst xtc xtp xtr xts xtx xxp xxx