zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz zzzz
Note: these 'words' (valid or invalid) are all the permutations of the word zzzz. These words are obtained by scrambling the letters in zzzz.