xfni fxni xnfi nxfi fnxi nfxi xfin fxin xifn ixfn fixn ifxn xnif nxif xinf ixnf nixf inxf fnix nfix finx ifnx nifx infx
Note: these 'words' (valid or invalid) are all the permutations of the word xfni. These words are obtained by scrambling the letters in xfni.