-er a-a a-b a-c aaa aab aac aae aam aar aas aax ab- aba abb abc abe abm abr abs abx ac- aca acb acc ace acm acr acs acx aea aeb aec aee aem aer aes aex ama amb amc ame amm amr ams amx ar- ara arb arc are arm arr ars arx as- asa asb asc ase asm asr ass asx ax- axa axe axm axr axs axx baa bab bac bae bam bar bas bax bba bbb bbc bbe bbm bbr bbs bbx bca bcb bcc bce bcm bcr bcs bcx be- bea beb bec bee bem ber bes bex bma bmb bmc bme bmm bmr bms bmx bra brb bre brm brr brs brx bsa bsb bsc bse bsm bsr bss bsx bxb bxm bxx c-- caa cab cac cae cam car cas cax cba cbb cbc cbe cbm cbr cbs cbx cca ccb ccc cce ccm ccr ccs ccx ce- cea ceb cec cee cem cer ces cex cma cmb cmc cme cmm cmr cms cmx cra crb crc cre crm crr crs crx csa csb csc cse csm csr css csx cxc cxr cxs cxx eaa eab eac eae eam ear eas eax eba ebb ebc ebe ebm ebr ebs ebx ec- eca ecb ecc ece ecm ecr ecs ecx eea eeb eec eee eem eer ees eex em- ema emb emc eme emm emr ems emx era erb erc ere erm err ers es- esa esb esc ese esm esr ess esx ex- exa exc exe exr exs exx m-r maa mab mac mae mam mar mas max mba mbb mbc mbe mbm mbr mbs mbx mc- mca mcb mcc mce mcm mcr mcs mcx mea meb mec mee mem mer mes mex mma mmb mmc mme mmm mmr mms mmx mra mrb mrc mre mrm mrr mrs mrx msa msb msc mse msm msr mss msx mxa mxc mxr mxs ra- raa rab rac rae ram rar ras rax rba rbb rbc rbe rbm rbr rbs rbx rca rcb rcc rce rcm rcr rcs rcx re- rea reb rec ree rem rer res rex rma rmb rmc rme rmm rmr rms rmx rra rrb rrc rrm rrr rrs rsa rsb rsc rse rsm rsr rss rsx rxr rxs saa sab sac sae sam sar sas sax sba sbb sbc sbe sbm sbr sbs sbx sca scb scc sce scm scr scs scx se- sea seb sec see sem ser ses sex sma smb smc sme smm smr sms smx sr- sra srb src sre srm srr srs srx ss- ssa ssb ssc sse ssm ssr sss ssx sxc sxm sxs xaa xac xam xar xas xbc xbe xbr xbx xcb xcr xcx xee xem xer xes xex xma xmc xmm xmr xms xmx xrc xrx xsa xsb xsc xsm xss xxx