firie ifrie friie rfiie irfie rifie fiire ifire fiire ifire iifre iifre friie rfiie firie ifrie rifie irfie irife riife iirfe iirfe riife irife firei ifrei friei rfiei irfei rifei fieri iferi feiri efiri iefri eifri freii rfeii ferii efrii refii erfii irefi riefi ierfi eirfi reifi erifi fiier ifier fiier ifier iifer iifer fieir ifeir feiir efiir iefir eifir fieir ifeir feiir efiir iefir eifir iiefr iiefr ieifr eiifr ieifr eiifr friei rfiei firei ifrei rifei irfei freii rfeii ferii efrii refii erfii fieri iferi feiri efiri iefri eifri riefi irefi reifi erifi ierfi eirfi irief riief iiref iiref riief irief ireif rieif ierif eirif reiif eriif iierf iierf ieirf eiirf ieirf eiirf rieif ireif reiif eriif ierif eirif
Note: these 'words' (valid or invalid) are all the permutations of the word firie. These words are obtained by scrambling the letters in firie.