pierst iperst peirst epirst ieprst eiprst pirest iprest priest rpiest irpest ripest perist eprist preist rpeist erpist repist ierpst eirpst irepst riepst eripst reipst piesrt ipesrt peisrt episrt iepsrt eipsrt pisert ipsert psiert spiert ispert sipert pesirt epsirt pseirt speirt espirt sepirt iesprt eisprt iseprt sieprt esiprt seiprt pirset iprset priset rpiset irpset ripset pisret ipsret psiret spiret ispret sipret prsiet rpsiet psriet spriet rspiet srpiet irspet rispet isrpet sirpet rsipet sripet persit eprsit presit rpesit erpsit repsit pesrit epsrit pserit sperit esprit seprit prseit rpseit psreit spreit rspeit srpeit erspit respit esrpit serpit rsepit srepit ierspt eirspt irespt riespt erispt reispt iesrpt eisrpt iserpt sierpt esirpt seirpt irsept risept isrept sirept rsiept sriept ersipt resipt esript seript rseipt sreipt pierts iperts peirts epirts ieprts eiprts pirets iprets priets rpiets irpets ripets perits eprits preits rpeits erpits repits ierpts eirpts irepts riepts eripts reipts pietrs ipetrs peitrs epitrs ieptrs eiptrs piters ipters ptiers tpiers itpers tipers petirs eptirs pteirs tpeirs etpirs tepirs ietprs eitprs iteprs tieprs etiprs teiprs pirtes iprtes prites rpites irptes riptes pitres iptres ptires tpires itpres tipres prties rpties ptries tpries rtpies trpies irtpes ritpes itrpes tirpes rtipes tripes pertis eprtis pretis rpetis erptis reptis petris eptris pteris tperis etpris tepris prteis rpteis ptreis tpreis rtpeis trpeis ertpis retpis etrpis terpis rtepis trepis iertps eirtps iretps rietps eritps reitps ietrps eitrps iterps tierps etirps teirps irteps riteps itreps tireps rtieps trieps ertips retips etrips terips rteips treips piestr ipestr peistr epistr iepstr eipstr pisetr ipsetr psietr spietr ispetr sipetr pesitr epsitr pseitr speitr espitr sepitr iesptr eisptr iseptr sieptr esiptr seiptr pietsr ipetsr peitsr epitsr ieptsr eiptsr pitesr iptesr ptiesr tpiesr itpesr tipesr petisr eptisr pteisr tpeisr etpisr tepisr ietpsr eitpsr itepsr tiepsr etipsr teipsr pister ipster psiter spiter ispter sipter pitser iptser ptiser tpiser itpser tipser pstier sptier ptsier tpsier stpier tspier istper sitper itsper tisper stiper tsiper pestir epstir psetir spetir esptir septir petsir eptsir ptesir tpesir etpsir tepsir psteir spteir ptseir tpseir stpeir tspeir estpir setpir etspir tespir stepir tsepir iestpr eistpr isetpr sietpr esitpr seitpr ietspr eitspr itespr tiespr etispr teispr istepr sitepr itsepr tisepr stiepr tsiepr estipr setipr etsipr tesipr steipr tseipr pirste iprste priste rpiste irpste ripste pisrte ipsrte psirte spirte isprte siprte prsite rpsite psrite sprite rspite srpite irspte rispte isrpte sirpte rsipte sripte pirtse iprtse pritse rpitse irptse riptse pitrse iptrse ptirse tpirse itprse tiprse prtise rptise ptrise tprise rtpise trpise irtpse ritpse itrpse tirpse rtipse tripse pistre ipstre psitre spitre isptre siptre pitsre iptsre ptisre tpisre itpsre tipsre pstire sptire ptsire tpsire stpire tspire istpre sitpre itspre tispre stipre tsipre prstie rpstie psrtie sprtie rsptie srptie prtsie rptsie ptrsie tprsie rtpsie trpsie pstrie sptrie ptsrie tpsrie stprie tsprie rstpie srtpie rtspie trspie strpie tsrpie irstpe ristpe isrtpe sirtpe rsitpe sritpe irtspe ritspe itrspe tirspe rtispe trispe istrpe sitrpe itsrpe tisrpe stirpe tsirpe rstipe srtipe rtsipe trsipe stripe tsripe persti eprsti presti rpesti erpsti repsti pesrti epsrti pserti sperti esprti seprti prseti rpseti psreti spreti rspeti srpeti erspti respti esrpti serpti rsepti srepti pertsi eprtsi pretsi rpetsi erptsi reptsi petrsi eptrsi ptersi tpersi etprsi teprsi prtesi rptesi ptresi tpresi rtpesi trpesi ertpsi retpsi etrpsi terpsi rtepsi trepsi pestri epstri psetri spetri esptri septri petsri eptsri ptesri tpesri etpsri tepsri psteri spteri ptseri tpseri stperi tsperi estpri setpri etspri tespri stepri tsepri prstei rpstei psrtei sprtei rsptei srptei prtsei rptsei ptrsei tprsei rtpsei trpsei pstrei sptrei ptsrei tpsrei stprei tsprei rstpei srtpei rtspei trspei strpei tsrpei erstpi restpi esrtpi sertpi rsetpi sretpi ertspi retspi etrspi terspi rtespi trespi estrpi setrpi etsrpi tesrpi sterpi tserpi rstepi srtepi rtsepi trsepi strepi tsrepi ierstp eirstp irestp riestp eristp reistp iesrtp eisrtp isertp siertp esirtp seirtp irsetp risetp isretp siretp rsietp srietp ersitp resitp esritp seritp rseitp sreitp iertsp eirtsp iretsp rietsp eritsp reitsp ietrsp eitrsp itersp tiersp etirsp teirsp irtesp ritesp itresp tiresp rtiesp triesp ertisp retisp etrisp terisp rteisp treisp iestrp eistrp isetrp sietrp esitrp seitrp ietsrp eitsrp itesrp tiesrp etisrp teisrp isterp siterp itserp tiserp stierp tsierp estirp setirp etsirp tesirp steirp tseirp irstep ristep isrtep sirtep rsitep sritep irtsep ritsep itrsep tirsep rtisep trisep istrep sitrep itsrep tisrep stirep tsirep rstiep srtiep rtsiep trsiep striep tsriep erstip restip esrtip sertip rsetip sretip ertsip retsip etrsip tersip rtesip tresip estrip setrip etsrip tesrip sterip tserip rsteip srteip rtseip trseip streip tsreip
Note: these 'words' (valid or invalid) are all the permutations of the word pierst. These words are obtained by scrambling the letters in pierst.