hkwh khwh hwkh whkh kwhh wkhh hkhw khhw hhkw hhkw khhw hkhw hwhk whhk hhwk hhwk whhk hwhk kwhh wkhh khwh hkwh whkh hwkh
Note: these 'words' (valid or invalid) are all the permutations of the word hkwh. These words are obtained by scrambling the letters in hkwh.