wltn lwtn wtln twln ltwn tlwn wlnt lwnt wnlt nwlt lnwt nlwt wtnl twnl wntl nwtl tnwl ntwl ltnw tlnw lntw nltw tnlw ntlw
Note: these 'words' (valid or invalid) are all the permutations of the word wltn. These words are obtained by scrambling the letters in wltn.