fiers ifers feirs efirs iefrs eifrs fires ifres fries rfies irfes rifes feris efris freis rfeis erfis refis ierfs eirfs irefs riefs erifs reifs fiesr ifesr feisr efisr iefsr eifsr fiser ifser fsier sfier isfer sifer fesir efsir fseir sfeir esfir sefir iesfr eisfr isefr siefr esifr seifr firse ifrse frise rfise irfse rifse fisre ifsre fsire sfire isfre sifre frsie rfsie fsrie sfrie rsfie srfie irsfe risfe isrfe sirfe rsife srife fersi efrsi fresi rfesi erfsi refsi fesri efsri fseri sferi esfri sefri frsei rfsei fsrei sfrei rsfei srfei ersfi resfi esrfi serfi rsefi srefi iersf eirsf iresf riesf erisf reisf iesrf eisrf iserf sierf esirf seirf irsef risef isref siref rsief srief ersif resif esrif serif rseif sreif
Note: these 'words' (valid or invalid) are all the permutations of the word fiers. These words are obtained by scrambling the letters in fiers.