sifrei isfrei sfirei fsirei ifsrei fisrei sirfei isrfei srifei rsifei irsfei risfei sfriei fsriei srfiei rsfiei frsiei rfsiei ifrsei firsei irfsei rifsei frisei rfisei siferi isferi sfieri fsieri ifseri fiseri siefri isefri seifri esifri iesfri eisfri sfeiri fseiri sefiri esfiri fesiri efsiri ifesri fiesri iefsri eifsri feisri efisri sirefi isrefi sriefi rsiefi irsefi risefi sierfi iserfi seirfi esirfi iesrfi eisrfi sreifi rseifi serifi esrifi resifi ersifi iresfi riesfi iersfi eirsfi reisfi erisfi sfreii fsreii srfeii rsfeii frseii rfseii sferii fserii sefrii esfrii fesrii efsrii srefii rsefii serfii esrfii resfii ersfii fresii rfesii fersii efrsii refsii erfsii ifresi firesi irfesi rifesi friesi rfiesi ifersi fiersi iefrsi eifrsi feirsi efirsi irefsi riefsi ierfsi eirfsi reifsi erifsi freisi rfeisi ferisi efrisi refisi erfisi sifrie isfrie sfirie fsirie ifsrie fisrie sirfie isrfie srifie rsifie irsfie risfie sfriie fsriie srfiie rsfiie frsiie rfsiie ifrsie firsie irfsie rifsie frisie rfisie sifire isfire sfiire fsiire ifsire fisire siifre isifre siifre isifre iisfre iisfre sfiire fsiire sifire isfire fisire ifsire ifisre fiisre iifsre iifsre fiisre ifisre sirife isrife sriife rsiife irsife risife siirfe isirfe siirfe isirfe iisrfe iisrfe sriife rsiife sirife isrife risife irsife irisfe riisfe iirsfe iirsfe riisfe irisfe sfriie fsriie srfiie rsfiie frsiie rfsiie sfirie fsirie sifrie isfrie fisrie ifsrie srifie rsifie sirfie isrfie risfie irsfie frisie rfisie firsie ifrsie rifsie irfsie ifrise firise irfise rifise friise rfiise ifirse fiirse iifrse iifrse fiirse ifirse irifse riifse iirfse iirfse riifse irifse friise rfiise firise ifrise rifise irfise sifeir isfeir sfieir fsieir ifseir fiseir siefir isefir seifir esifir iesfir eisfir sfeiir fseiir sefiir esfiir fesiir efsiir ifesir fiesir iefsir eifsir feisir efisir sifier isfier sfiier fsiier ifsier fisier siifer isifer siifer isifer iisfer iisfer sfiier fsiier sifier isfier fisier ifsier ifiser fiiser iifser iifser fiiser ifiser sieifr iseifr seiifr esiifr iesifr eisifr siiefr isiefr siiefr isiefr iisefr iisefr seiifr esiifr sieifr iseifr eisifr iesifr ieisfr eiisfr iiesfr iiesfr eiisfr ieisfr sfeiir fseiir sefiir esfiir fesiir efsiir sfieir fsieir sifeir isfeir fiseir ifseir seifir esifir siefir isefir eisfir iesfir feisir efisir fiesir ifesir eifsir iefsir ifeisr fieisr iefisr eifisr feiisr efiisr ifiesr fiiesr iifesr iifesr fiiesr ifiesr ieifsr eiifsr iiefsr iiefsr eiifsr ieifsr feiisr efiisr fieisr ifeisr eifisr iefisr sireif isreif srieif rsieif irseif riseif sierif iserif seirif esirif iesrif eisrif sreiif rseiif seriif esriif resiif ersiif iresif riesif iersif eirsif reisif erisif sirief isrief sriief rsiief irsief risief siiref isiref siiref isiref iisref iisref sriief rsiief sirief isrief risief irsief irisef riisef iirsef iirsef riisef irisef sieirf iseirf seiirf esiirf iesirf eisirf siierf isierf siierf isierf iiserf iiserf seiirf esiirf sieirf iseirf eisirf iesirf ieisrf eiisrf iiesrf iiesrf eiisrf ieisrf sreiif rseiif seriif esriif resiif ersiif srieif rsieif sireif isreif riseif irseif seirif esirif sierif iserif eisrif iesrif reisif erisif riesif iresif eirsif iersif ireisf rieisf ierisf eirisf reiisf eriisf iriesf riiesf iiresf iiresf riiesf iriesf ieirsf eiirsf iiersf iiersf eiirsf ieirsf reiisf eriisf rieisf ireisf eirisf ierisf sfreii fsreii srfeii rsfeii frseii rfseii sferii fserii sefrii esfrii fesrii efsrii srefii rsefii serfii esrfii resfii ersfii fresii rfesii fersii efrsii refsii erfsii sfriei fsriei srfiei rsfiei frsiei rfsiei sfirei fsirei sifrei isfrei fisrei ifsrei srifei rsifei sirfei isrfei risfei irsfei frisei rfisei firsei ifrsei rifsei irfsei sfeiri fseiri sefiri esfiri fesiri efsiri sfieri fsieri siferi isferi fiseri ifseri seifri esifri siefri isefri eisfri iesfri feisri efisri fiesri ifesri eifsri iefsri sreifi rseifi serifi esrifi resifi ersifi sriefi rsiefi sirefi isrefi risefi irsefi seirfi esirfi sierfi iserfi eisrfi iesrfi reisfi erisfi riesfi iresfi eirsfi iersfi freisi rfeisi ferisi efrisi refisi erfisi friesi rfiesi firesi ifresi rifesi irfesi feirsi efirsi fiersi ifersi eifrsi iefrsi reifsi erifsi riefsi irefsi eirfsi ierfsi ifreis fireis irfeis rifeis frieis rfieis iferis fieris iefris eifris feiris efiris irefis riefis ierfis eirfis reifis erifis freiis rfeiis feriis efriis refiis erfiis ifries firies irfies rifies friies rfiies ifires fiires iifres iifres fiires ifires irifes riifes iirfes iirfes riifes irifes friies rfiies firies ifries rifies irfies ifeirs fieirs iefirs eifirs feiirs efiirs ifiers fiiers iifers iifers fiiers ifiers ieifrs eiifrs iiefrs iiefrs eiifrs ieifrs feiirs efiirs fieirs ifeirs eifirs iefirs ireifs rieifs ierifs eirifs reiifs eriifs iriefs riiefs iirefs iirefs riiefs iriefs ieirfs eiirfs iierfs iierfs eiirfs ieirfs reiifs eriifs rieifs ireifs eirifs ierifs freiis rfeiis feriis efriis refiis erfiis frieis rfieis fireis ifreis rifeis irfeis feiris efiris fieris iferis eifris iefris reifis erifis riefis irefis eirfis ierfis
Note: these 'words' (valid or invalid) are all the permutations of the word sifrei. These words are obtained by scrambling the letters in sifrei.