seres esres srees rsees erses reses seers esers seers esers eesrs eesrs srees rsees seres esres reses erses eress reess eerss eerss reess eress serse esrse srese rsese ersse resse sesre essre ssere ssere essre sesre srsee rssee ssree ssree rssee srsee ersse resse esrse serse rsese srese seesr esesr seesr esesr eessr eessr seser esser sseer sseer esser seser seser esser sseer sseer esser seser eessr eessr esesr seesr esesr seesr srese rsese serse esrse resse ersse srsee rssee ssree ssree rssee srsee sesre essre ssere ssere essre sesre resse ersse rsese srese esrse serse eress reess eerss eerss reess eress erses reses esres seres rsees srees eesrs eesrs esers seers esers seers reses erses rsees srees esres seres
Note: these 'words' (valid or invalid) are all the permutations of the word seres. These words are obtained by scrambling the letters in seres.