-er c-- ccc cce ccn ccp ccr cct ccx ce- cec cee cen cep cer cet cex cn- cnc cne cnn cnp cnr cnt cnx cpc cpe cpn cpp cpr cpt cpx crc cre crn crp crr crt crx ctc cte ctn ctp ctr ctt ctx cxc cxp cxr cxt cxx ec- ecc ece ecn ecr ect ecx eec eee een eep eer eet eex en- enc ene enn enp enr ent ep- epc epe epn epp epr ept epx erc ere ern erp err ert etc ete etn etp etr ett etx ex- exc exe exp exr ext exx ncc nce ncn ncp ncr nct ncx ne- nec nee nen nep ner net nex nnc nne nnn nnp nnt npc npe npn npp npr npt nrc nre nrn nrp nrr nrt nrx ntc nte ntn ntp ntr ntt ntx nxc nxt p-p pcc pce pcn pcp pcr pct pcx pec pee pen pep per pet pex pn- pnc pne pnn pnp pnr pnt pnx ppc ppe ppn ppp ppr ppt ppx prc pre prn prp prr prt prx pt- ptc pte ptn ptp ptr ptt ptx pxc pxe pxr pxt rcc rce rcn rcp rcr rct rcx re- rec ree ren rep rer ret rex rnc rnn rnp rnr rnt rpc rpe rpn rpp rpr rpt rpx rrc rrn rrp rrr rrt rtc rte rtn rtp rtr rtt rtx rxp rxr t-x tcc tce tcn tcp tcr tct tcx te- tec tee ten tep ter tet tex tnc tne tnn tnp tnr tnt tnx tpc tpe tpn tpp tpr tpt tpx trc tre trn trp trr trt trx ttc tte ttn ttp ttr ttt ttx txe txn txt xcp xcr xcx xee xen xep xer xet xex xnc xpc xpe xpn xpp xpt xrc xrt xrx xtc xtp xtr xtx xxp xxx