shifts hsifts sihfts ishfts hisfts ihsfts shfits hsfits sfhits fshits hfsits fhsits sifhts isfhts sfihts fsihts ifshts fishts hifsts ihfsts hfists fhists ifhsts fihsts shitfs hsitfs sihtfs ishtfs histfs ihstfs shtifs hstifs sthifs tshifs htsifs thsifs sithfs isthfs stihfs tsihfs itshfs tishfs hitsfs ihtsfs htisfs thisfs ithsfs tihsfs shftis hsftis sfhtis fshtis hfstis fhstis shtfis hstfis sthfis tshfis htsfis thsfis sfthis fsthis stfhis tsfhis ftshis tfshis hftsis fhtsis htfsis thfsis fthsis tfhsis sifths isfths sfiths fsiths ifsths fisths sitfhs istfhs stifhs tsifhs itsfhs tisfhs sftihs fstihs stfihs tsfihs ftsihs tfsihs iftshs fitshs itfshs tifshs ftishs tfishs hiftss ihftss hfitss fhitss ifhtss fihtss hitfss ihtfss htifss thifss ithfss tihfss hftiss fhtiss htfiss thfiss fthiss tfhiss ifthss fithss itfhss tifhss ftihss tfihss shifst hsifst sihfst ishfst hisfst ihsfst shfist hsfist sfhist fshist hfsist fhsist sifhst isfhst sfihst fsihst ifshst fishst hifsst ihfsst hfisst fhisst ifhsst fihsst shisft hsisft sihsft ishsft hissft ihssft shsift hssift sshift sshift hssift shsift sishft isshft ssihft ssihft isshft sishft hissft ihssft hsisft shisft ishsft sihsft shfsit hsfsit sfhsit fshsit hfssit fhssit shsfit hssfit sshfit sshfit hssfit shsfit sfshit fsshit ssfhit ssfhit fsshit sfshit hfssit fhssit hsfsit shfsit fshsit sfhsit sifsht isfsht sfisht fsisht ifssht fissht sisfht issfht ssifht ssifht issfht sisfht sfsiht fssiht ssfiht ssfiht fssiht sfsiht ifssht fissht isfsht sifsht fsisht sfisht hifsst ihfsst hfisst fhisst ifhsst fihsst hisfst ihsfst hsifst shifst ishfst sihfst hfsist fhsist hsfist shfist fshist sfhist ifshst fishst isfhst sifhst fsihst sfihst shitsf hsitsf sihtsf ishtsf histsf ihstsf shtisf hstisf sthisf tshisf htsisf thsisf sithsf isthsf stihsf tsihsf itshsf tishsf hitssf ihtssf htissf thissf ithssf tihssf shistf hsistf sihstf ishstf hisstf ihsstf shsitf hssitf sshitf sshitf hssitf shsitf sishtf isshtf ssihtf ssihtf isshtf sishtf hisstf ihsstf hsistf shistf ishstf sihstf shtsif hstsif sthsif tshsif htssif thssif shstif hsstif sshtif sshtif hsstif shstif stshif tsshif ssthif ssthif tsshif stshif htssif thssif hstsif shtsif tshsif sthsif sitshf istshf stishf tsishf itsshf tisshf sisthf issthf ssithf ssithf issthf sisthf stsihf tssihf sstihf sstihf tssihf stsihf itsshf tisshf istshf sitshf tsishf stishf hitssf ihtssf htissf thissf ithssf tihssf histsf ihstsf hsitsf shitsf ishtsf sihtsf htsisf thsisf hstisf shtisf tshisf sthisf itshsf tishsf isthsf sithsf tsihsf stihsf shftsi hsftsi sfhtsi fshtsi hfstsi fhstsi shtfsi hstfsi sthfsi tshfsi htsfsi thsfsi sfthsi fsthsi stfhsi tsfhsi ftshsi tfshsi hftssi fhtssi htfssi thfssi fthssi tfhssi shfsti hsfsti sfhsti fshsti hfssti fhssti shsfti hssfti sshfti sshfti hssfti shsfti sfshti fsshti ssfhti ssfhti fsshti sfshti hfssti fhssti hsfsti shfsti fshsti sfhsti shtsfi hstsfi sthsfi tshsfi htssfi thssfi shstfi hsstfi sshtfi sshtfi hsstfi shstfi stshfi tsshfi ssthfi ssthfi tsshfi stshfi htssfi thssfi hstsfi shtsfi tshsfi sthsfi sftshi fstshi stfshi tsfshi ftsshi tfsshi sfsthi fssthi ssfthi ssfthi fssthi sfsthi stsfhi tssfhi sstfhi sstfhi tssfhi stsfhi ftsshi tfsshi fstshi sftshi tsfshi stfshi hftssi fhtssi htfssi thfssi fthssi tfhssi hfstsi fhstsi hsftsi shftsi fshtsi sfhtsi htsfsi thsfsi hstfsi shtfsi tshfsi sthfsi ftshsi tfshsi fsthsi sfthsi tsfhsi stfhsi siftsh isftsh sfitsh fsitsh ifstsh fistsh sitfsh istfsh stifsh tsifsh itsfsh tisfsh sftish fstish stfish tsfish ftsish tfsish iftssh fitssh itfssh tifssh ftissh tfissh sifsth isfsth sfisth fsisth ifssth fissth sisfth issfth ssifth ssifth issfth sisfth sfsith fssith ssfith ssfith fssith sfsith ifssth fissth isfsth sifsth fsisth sfisth sitsfh istsfh stisfh tsisfh itssfh tissfh sistfh isstfh ssitfh ssitfh isstfh sistfh stsifh tssifh sstifh sstifh tssifh stsifh itssfh tissfh istsfh sitsfh tsisfh stisfh sftsih fstsih stfsih tsfsih ftssih tfssih sfstih fsstih ssftih ssftih fsstih sfstih stsfih tssfih sstfih sstfih tssfih stsfih ftssih tfssih fstsih sftsih tsfsih stfsih iftssh fitssh itfssh tifssh ftissh tfissh ifstsh fistsh isftsh siftsh fsitsh sfitsh itsfsh tisfsh istfsh sitfsh tsifsh stifsh ftsish tfsish fstish sftish tsfish stfish hiftss ihftss hfitss fhitss ifhtss fihtss hitfss ihtfss htifss thifss ithfss tihfss hftiss fhtiss htfiss thfiss fthiss tfhiss ifthss fithss itfhss tifhss ftihss tfihss hifsts ihfsts hfists fhists ifhsts fihsts hisfts ihsfts hsifts shifts ishfts sihfts hfsits fhsits hsfits shfits fshits sfhits ifshts fishts isfhts sifhts fsihts sfihts hitsfs ihtsfs htisfs thisfs ithsfs tihsfs histfs ihstfs hsitfs shitfs ishtfs sihtfs htsifs thsifs hstifs shtifs tshifs sthifs itshfs tishfs isthfs sithfs tsihfs stihfs hftsis fhtsis htfsis thfsis fthsis tfhsis hfstis fhstis hsftis shftis fshtis sfhtis htsfis thsfis hstfis shtfis tshfis sthfis ftshis tfshis fsthis sfthis tsfhis stfhis iftshs fitshs itfshs tifshs ftishs tfishs ifsths fisths isfths sifths fsiths sfiths itsfhs tisfhs istfhs sitfhs tsifhs stifhs ftsihs tfsihs fstihs sftihs tsfihs stfihs
Note: these 'words' (valid or invalid) are all the permutations of the word shifts. These words are obtained by scrambling the letters in shifts.