kdrh dkrh krdh rkdh drkh rdkh kdhr dkhr khdr hkdr dhkr hdkr krhd rkhd khrd hkrd rhkd hrkd drhk rdhk dhrk hdrk rhdk hrdk
Note: these 'words' (valid or invalid) are all the permutations of the word kdrh. These words are obtained by scrambling the letters in kdrh.