gghh gghh ghgh hggh ghgh hggh gghh gghh ghgh hggh ghgh hggh ghhg hghg ghhg hghg hhgg hhgg ghhg hghg ghhg hghg hhgg hhgg
Note: these 'words' (valid or invalid) are all the permutations of the word gghh. These words are obtained by scrambling the letters in gghh.