a-a a-b aaa aab aae aam aas aax ab- aba abb abe abm abs abx aea aeb aee aem aes aex ama amb ame amm ams amx as- asa asb ase asm ass asx ax- axa axe axm axs axx baa bab bae bam bas bax bba bbb bbe bbm bbs bbx be- bea beb bee bem bes bex bma bmb bme bmm bms bmx bsa bsb bse bsm bss bsx bxb bxm bxx eaa eab eae eam eas eax eba ebb ebe ebm ebs ebx eea eeb eee eem ees eex em- ema emb eme emm ems emx es- esa esb ese esm ess esx ex- exa exe exs exx maa mab mae mam mas max mba mbb mbe mbm mbs mbx mea meb mee mem mes mex mma mmb mme mmm mms mmx msa msb mse msm mss msx mxa mxs saa sab sae sam sas sax sba sbb sbe sbm sbs sbx se- sea seb see sem ses sex sma smb sme smm sms smx ss- ssa ssb sse ssm sss ssx sxm sxs xaa xam xas xbe xbx xee xem xes xex xma xmm xms xmx xsa xsb xsm xss xxx