nexm enxm nxem xnem exnm xenm nemx enmx nmex mnex emnx menx nxme xnme nmxe mnxe xmne mxne exmn xemn emxn mexn xmen mxen
Note: these 'words' (valid or invalid) are all the permutations of the word nexm. These words are obtained by scrambling the letters in nexm.