lych ylch lcyh clyh yclh cylh lyhc ylhc lhyc hlyc yhlc hylc lchy clhy lhcy hlcy chly hcly ychl cyhl yhcl hycl chyl hcyl
Note: these 'words' (valid or invalid) are all the permutations of the word lych. These words are obtained by scrambling the letters in lych.