-er a-a a-c a-t aaa aac aae aam aar aat aax ac- aca acc ace acm acr act acx aea aec aee aem aer aet aex ama amc ame amm amr amt amx ar- ara arc are arm arr art arx at- ata atc ate atm atr att atx ax- axa axe axm axr axt axx c-- caa cac cae cam car cat cax cca ccc cce ccm ccr cct ccx ce- cea cec cee cem cer cet cex cma cmc cme cmm cmr cmt cmx cra crc cre crm crr crt crx cta ctc cte ctm ctr ctt ctx cxc cxr cxt cxx eaa eac eae eam ear eat eax ec- eca ecc ece ecm ecr ect ecx eea eec eee eem eer eet eex em- ema emc eme emm emr emt emx era erc ere erm err ert eta etc ete etm etr ett etx ex- exa exc exe exr ext exx m-r maa mac mae mam mar mat max mc- mca mcc mce mcm mcr mct mcx mea mec mee mem mer met mex mma mmc mme mmm mmr mmt mmx mra mrc mre mrm mrr mrt mrx mta mtc mte mtm mtr mtt mtx mxa mxc mxr ra- raa rac rae ram rar rat rax rca rcc rce rcm rcr rct rcx re- rea rec ree rem rer ret rex rma rmc rme rmm rmr rmt rmx rra rrc rrm rrr rrt rta rtc rte rtm rtr rtt rtx rxr t-x taa tac tae tam tar tat tax tca tcc tce tcm tcr tct tcx te- tea tec tee tem ter tet tex tma tmc tme tmm tmr tmt tmx tra trc tre trm trr trt trx tta ttc tte ttm ttr ttt ttx txe txt xaa xac xam xar xat xcr xcx xee xem xer xet xex xma xmc xmm xmr xmt xmx xrc xrt xrx xtc xtm xtr xtx xxx