xnca nxca xcna cxna ncxa cnxa xnac nxac xanc axnc naxc anxc xcan cxan xacn axcn caxn acxn ncax cnax nacx ancx canx acnx
Note: these 'words' (valid or invalid) are all the permutations of the word xnca. These words are obtained by scrambling the letters in xnca.