screw csrew srcew rscew crsew rcsew scerw cserw secrw escrw cesrw ecsrw srecw rsecw sercw esrcw rescw erscw cresw rcesw cersw ecrsw recsw ercsw scrwe csrwe srcwe rscwe crswe rcswe scwre cswre swcre wscre cwsre wcsre srwce rswce swrce wsrce rwsce wrsce crwse rcwse cwrse wcrse rwcse wrcse scewr csewr secwr escwr ceswr ecswr scwer cswer swcer wscer cwser wcser sewcr eswcr swecr wsecr ewscr wescr cewsr ecwsr cwesr wcesr ewcsr wecsr srewc rsewc serwc esrwc reswc erswc srwec rswec swrec wsrec rwsec wrsec sewrc eswrc swerc wserc ewsrc wesrc rewsc erwsc rwesc wresc ewrsc wersc crews rcews cerws ecrws recws ercws crwes rcwes cwres wcres rwces wrces cewrs ecwrs cwers wcers ewcrs wecrs rewcs erwcs rwecs wrecs ewrcs wercs
Note: these 'words' (valid or invalid) are all the permutations of the word screw. These words are obtained by scrambling the letters in screw.