tress rtess terss etrss retss ertss trses rtses tsres stres rstes srtes tesrs etsrs tsers sters estrs setrs rests ersts rsets srets esrts serts tress rtess terss etrss retss ertss trses rtses tsres stres rstes srtes tesrs etsrs tsers sters estrs setrs rests ersts rsets srets esrts serts trsse rtsse tsrse strse rstse srtse trsse rtsse tsrse strse rstse srtse tssre stsre tssre stsre sstre sstre rsste srste rsste srste ssrte ssrte tessr etssr tsesr stesr estsr setsr tessr etssr tsesr stesr estsr setsr tsser stser tsser stser sster sster esstr sestr esstr sestr ssetr ssetr resst ersst rsest srest esrst serst resst ersst rsest srest esrst serst rsset srset rsset srset ssret ssret essrt sesrt essrt sesrt ssert ssert
Note: these 'words' (valid or invalid) are all the permutations of the word tress. These words are obtained by scrambling the letters in tress.