-er a-a a-b a-c a-t aaa aab aac aae aam aar aat aax ab- aba abb abc abe abm abr abt abx ac- aca acb acc ace acm acr act acx aea aeb aec aee aem aer aet aex ama amb amc ame amm amr amt amx ar- ara arb arc are arm arr art arx at- ata atb atc ate atm atr att atx ax- axa axe axm axr axt axx baa bab bac bae bam bar bat bax bba bbb bbc bbe bbm bbr bbt bbx bca bcb bcc bce bcm bcr bct bcx be- bea beb bec bee bem ber bet bex bma bmb bmc bme bmm bmr bmt bmx bra brb bre brm brr brt brx bta btb btc bte btm btr btt btx bxb bxm bxx c-- caa cab cac cae cam car cat cax cba cbb cbc cbe cbm cbr cbt cbx cca ccb ccc cce ccm ccr cct ccx ce- cea ceb cec cee cem cer cet cex cma cmb cmc cme cmm cmr cmt cmx cra crb crc cre crm crr crt crx cta ctb ctc cte ctm ctr ctt ctx cxc cxr cxt cxx eaa eab eac eae eam ear eat eax eba ebb ebc ebe ebm ebr ebt ebx ec- eca ecb ecc ece ecm ecr ect ecx eea eeb eec eee eem eer eet eex em- ema emb emc eme emm emr emt emx era erb erc ere erm err ert eta etb etc ete etm etr ett etx ex- exa exc exe exr ext exx m-r maa mab mac mae mam mar mat max mba mbb mbc mbe mbm mbr mbt mbx mc- mca mcb mcc mce mcm mcr mct mcx mea meb mec mee mem mer met mex mma mmb mmc mme mmm mmr mmt mmx mra mrb mrc mre mrm mrr mrt mrx mta mtb mtc mte mtm mtr mtt mtx mxa mxc mxr ra- raa rab rac rae ram rar rat rax rba rbb rbc rbe rbm rbr rbt rbx rca rcb rcc rce rcm rcr rct rcx re- rea reb rec ree rem rer ret rex rma rmb rmc rme rmm rmr rmt rmx rra rrb rrc rrm rrr rrt rta rtb rtc rte rtm rtr rtt rtx rxr t-x taa tab tac tae tam tar tat tax tba tbb tbc tbe tbm tbr tbt tca tcb tcc tce tcm tcr tct tcx te- tea teb tec tee tem ter tet tex tma tmb tmc tme tmm tmr tmt tmx tra trb trc tre trm trr trt trx tta ttb ttc tte ttm ttr ttt ttx txe txt xaa xac xam xar xat xbc xbe xbr xbx xcb xcr xcx xee xem xer xet xex xma xmc xmm xmr xmt xmx xrc xrt xrx xtc xtm xtr xtx xxx