fumf ufmf fmuf mfuf umff muff fufm uffm ffum ffum uffm fufm fmfu mffu ffmu ffmu mffu fmfu umff muff ufmf fumf mfuf fmuf
Note: these 'words' (valid or invalid) are all the permutations of the word fumf. These words are obtained by scrambling the letters in fumf.