ruers urers reurs erurs uerrs eurrs rures urres rrues rrues urres rures rerus errus rreus rreus errus rerus uerrs eurrs urers ruers erurs reurs ruesr uresr reusr erusr uersr eursr ruser urser rsuer sruer usrer surer resur ersur rseur sreur esrur serur uesrr eusrr userr suerr esurr seurr rurse urrse rruse rruse urrse rurse rusre ursre rsure srure usrre surre rrsue rrsue rsrue srrue rsrue srrue ursre rusre usrre surre rsure srure rersu errsu rresu rresu errsu rersu resru ersru rseru sreru esrru serru rrseu rrseu rsreu srreu rsreu srreu ersru resru esrru serru rseru sreru uersr eursr uresr ruesr erusr reusr uesrr eusrr userr suerr esurr seurr urser ruser usrer surer rsuer sruer ersur resur esrur serur rseur sreur
Note: these 'words' (valid or invalid) are all the permutations of the word ruers. These words are obtained by scrambling the letters in ruers.