freit rfeit ferit efrit refit erfit friet rfiet firet ifret rifet irfet feirt efirt fiert ifert eifrt iefrt reift erift rieft ireft eirft ierft freti rfeti ferti efrti refti erfti frtei rftei ftrei tfrei rtfei trfei fetri eftri fteri tferi etfri tefri retfi ertfi rtefi trefi etrfi terfi frite rfite firte ifrte rifte irfte frtie rftie ftrie tfrie rtfie trfie fitre iftre ftire tfire itfre tifre ritfe irtfe rtife trife itrfe tirfe feitr efitr fietr ifetr eiftr ieftr fetir eftir fteir tfeir etfir tefir fiter ifter ftier tfier itfer tifer eitfr ietfr etifr teifr itefr tiefr reitf eritf rietf iretf eirtf iertf retif ertif rteif treif etrif terif ritef irtef rtief trief itref tiref eitrf ietrf etirf teirf iterf tierf
Note: these 'words' (valid or invalid) are all the permutations of the word freit. These words are obtained by scrambling the letters in freit.