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