-er a-a a-c a-t aaa aac aae aam aar aas aat aax ac- aca acc ace acm acr acs act acx aea aec aee aem aer aes aet aex ama amc ame amm amr ams amt amx ar- ara arc are arm arr ars art arx as- asa asc ase asm asr ass ast asx at- ata atc ate atm atr ats att atx ax- axa axe axm axr axs axt axx c-- caa cac cae cam car cas cat cax cca ccc cce ccm ccr ccs cct ccx ce- cea cec cee cem cer ces cet cex cma cmc cme cmm cmr cms cmt cmx cra crc cre crm crr crs crt crx csa csc cse csm csr css cst csx cta ctc cte ctm ctr cts ctt ctx cxc cxr cxs cxt cxx eaa eac eae eam ear eas eat eax ec- eca ecc ece ecm ecr ecs ect ecx eea eec eee eem eer ees eet eex em- ema emc eme emm emr ems emt emx era erc ere erm err ers ert es- esa esc ese esm esr ess est esx eta etc ete etm etr ets ett etx ex- exa exc exe exr exs ext exx m-r maa mac mae mam mar mas mat max mc- mca mcc mce mcm mcr mcs mct mcx mea mec mee mem mer mes met mex mma mmc mme mmm mmr mms mmt mmx mra mrc mre mrm mrr mrs mrt mrx msa msc mse msm msr mss mst msx mta mtc mte mtm mtr mts mtt mtx mxa mxc mxr mxs ra- raa rac rae ram rar ras rat rax rca rcc rce rcm rcr rcs rct rcx re- rea rec ree rem rer res ret rex rma rmc rme rmm rmr rms rmt rmx rra rrc rrm rrr rrs rrt rsa rsc rse rsm rsr rss rst rsx rta rtc rte rtm rtr rts rtt rtx rxr rxs saa sac sae sam sar sas sat sax sca scc sce scm scr scs sct scx se- sea sec see sem ser ses set sex sma smc sme smm smr sms smt smx sr- sra src sre srm srr srs srt srx ss- ssa ssc sse ssm ssr sss sst ssx sta stc ste stm str sts stt stx sxc sxm sxs sxt t-x taa tac tae tam tar tas tat tax tca tcc tce tcm tcr tcs tct tcx te- tea tec tee tem ter tes tet tex tma tmc tme tmm tmr tms tmt tmx tra trc tre trm trr trs trt trx tsa tsc tse tsm tsr tss tst tsx tta ttc tte ttm ttr tts ttt ttx txe txs txt xaa xac xam xar xas xat xcr xcx xee xem xer xes xet xex xma xmc xmm xmr xms xmt xmx xrc xrt xrx xsa xsc xsm xss xst xtc xtm xtr xts xtx xxx