tilfs itlfs tlifs ltifs iltfs litfs tifls itfls tfils ftils iftls fitls tlfis ltfis tflis ftlis lftis fltis ilfts lifts iflts filts lfits flits tilsf itlsf tlisf ltisf iltsf litsf tislf itslf tsilf stilf istlf sitlf tlsif ltsif tslif stlif lstif sltif ilstf listf isltf siltf lsitf slitf tifsl itfsl tfisl ftisl iftsl fitsl tisfl itsfl tsifl stifl istfl sitfl tfsil ftsil tsfil stfil fstil sftil ifstl fistl isftl siftl fsitl sfitl tlfsi ltfsi tflsi ftlsi lftsi fltsi tlsfi ltsfi tslfi stlfi lstfi sltfi tfsli ftsli tsfli stfli fstli sftli lfsti flsti lsfti slfti fslti sflti ilfst lifst iflst filst lfist flist ilsft lisft islft silft lsift slift ifslt fislt isflt siflt fsilt sfilt lfsit flsit lsfit slfit fslit sflit
Note: these 'words' (valid or invalid) are all the permutations of the word tilfs. These words are obtained by scrambling the letters in tilfs.