khaf hkaf kahf akhf hakf ahkf khfa hkfa kfha fkha hfka fhka kafh akfh kfah fkah afkh fakh hafk ahfk hfak fhak afhk fahk
Note: these 'words' (valid or invalid) are all the permutations of the word khaf. These words are obtained by scrambling the letters in khaf.