-er -th c-- ccc cce cch ccr ccs cct ccx ce- cec cee ceh cer ces cet cex ch- chc che chh chr chs cht chx crc cre crh crr crs crt crx csc cse csh csr css cst csx ctc cte cth ctr cts ctt ctx cxc cxh cxr cxs cxt cxx ec- ecc ece ech ecr ecs ect ecx eec eee eer ees eet eex ehc ehe ehh ehr ehs eht erc ere erh err ers ert es- esc ese esh esr ess est esx etc ete eth etr ets ett etx ex- exc exe exh exr exs ext exx hcc hce hch hcr hcs hct he- hec hee heh her hes het hex hhc hhe hhh hhr hhs hht hr- hrc hre hrh hrr hrs hrt hsc hse hsh hsr hss hst hsx htc hte hth htr hts htt htx hxc rcc rce rch rcr rcs rct rcx re- rec ree reh rer res ret rex rh- rhc rhe rhh rhr rhs rht rrc rrh rrr rrs rrt rsc rse rsh rsr rss rst rsx rtc rte rtr rts rtt rtx rxr rxs scc sce sch scr scs sct scx se- sec see seh ser ses set sex sh- shc she shh shr shs sht sr- src sre srh srr srs srt srx ss- ssc sse ssh ssr sss sst ssx stc ste sth str sts stt stx sxc sxs sxt t-x tcc tce tch tcr tcs tct tcx te- tec tee teh ter tes tet tex th- thc the thh thr ths tht thx trc tre trh trr trs trt trx tsc tse tsh tsr tss tst tsx ttc tte tth ttr tts ttt ttx txe txs txt xch xcr xcx xee xer xes xet xex xht xrc xrt xrx xsc xss xst xtc xtr xts xtx xxx