aqrt qart arqt raqt qrat rqat aqtr qatr atqr taqr qtar tqar artq ratq atrq tarq rtaq traq qrta rqta qtra tqra rtqa trqa
Note: these 'words' (valid or invalid) are all the permutations of the word aqrt. These words are obtained by scrambling the letters in aqrt.