knur nkur kunr uknr nukr unkr knru nkru krnu rknu nrku rnku kurn ukrn krun rkun urkn rukn nurk unrk nruk rnuk urnk runk
Note: these 'words' (valid or invalid) are all the permutations of the word knur. These words are obtained by scrambling the letters in knur.