dixy idxy dxiy xdiy ixdy xidy diyx idyx dyix ydix iydx yidx dxyi xdyi dyxi ydxi xydi yxdi ixyd xiyd iyxd yixd xyid yxid
Note: these 'words' (valid or invalid) are all the permutations of the word dixy. These words are obtained by scrambling the letters in dixy.