uffv fufv uffv fufv ffuv ffuv ufvf fuvf uvff vuff fvuf vfuf ufvf fuvf uvff vuff fvuf vfuf ffvu ffvu fvfu vffu fvfu vffu
Note: these 'words' (valid or invalid) are all the permutations of the word uffv. These words are obtained by scrambling the letters in uffv.