fhun hfun fuhn ufhn hufn uhfn fhnu hfnu fnhu nfhu hnfu nhfu funh ufnh fnuh nfuh unfh nufh hunf uhnf hnuf nhuf unhf nuhf
Note: these 'words' (valid or invalid) are all the permutations of the word fhun. These words are obtained by scrambling the letters in fhun.