feist efist fiest ifest eifst iefst fesit efsit fseit sfeit esfit sefit fiset ifset fsiet sfiet isfet sifet eisft iesft esift seift iseft sieft feits efits fiets ifets eifts iefts fetis eftis fteis tfeis etfis tefis fites iftes fties tfies itfes tifes eitfs ietfs etifs teifs itefs tiefs festi efsti fseti sfeti esfti sefti fetsi eftsi ftesi tfesi etfsi tefsi fstei sftei ftsei tfsei stfei tsfei estfi setfi etsfi tesfi stefi tsefi fiste ifste fsite sfite isfte sifte fitse iftse ftise tfise itfse tifse fstie sftie ftsie tfsie stfie tsfie istfe sitfe itsfe tisfe stife tsife eistf iestf esitf seitf isetf sietf eitsf ietsf etisf teisf itesf tiesf estif setif etsif tesif steif tseif istef sitef itsef tisef stief tsief
Note: these 'words' (valid or invalid) are all the permutations of the word feist. These words are obtained by scrambling the letters in feist.