xdey dxey xedy exdy dexy edxy xdye dxye xyde yxde dyxe ydxe xeyd exyd xyed yxed eyxd yexd deyx edyx dyex ydex eydx yedx
Note: these 'words' (valid or invalid) are all the permutations of the word xdey. These words are obtained by scrambling the letters in xdey.