staff tsaff satff astff tasff atsff stfaf tsfaf sftaf fstaf tfsaf ftsaf saftf asftf sfatf fsatf afstf fastf tafsf atfsf tfasf ftasf aftsf fatsf staff tsaff satff astff tasff atsff stfaf tsfaf sftaf fstaf tfsaf ftsaf saftf asftf sfatf fsatf afstf fastf tafsf atfsf tfasf ftasf aftsf fatsf stffa tsffa sftfa fstfa tfsfa ftsfa stffa tsffa sftfa fstfa tfsfa ftsfa sffta fsfta sffta fsfta ffsta ffsta tffsa ftfsa tffsa ftfsa fftsa fftsa safft asfft sfaft fsaft afsft fasft safft asfft sfaft fsaft afsft fasft sffat fsfat sffat fsfat ffsat ffsat affst fafst affst fafst ffast ffast taffs atffs tfafs ftafs aftfs fatfs taffs atffs tfafs ftafs aftfs fatfs tffas ftfas tffas ftfas fftas fftas affts fafts affts fafts ffats ffats
Note: these 'words' (valid or invalid) are all the permutations of the word staff. These words are obtained by scrambling the letters in staff.