furrs ufrrs frurs rfurs urfrs rufrs furrs ufrrs frurs rfurs urfrs rufrs frrus rfrus frrus rfrus rrfus rrfus urrfs rurfs urrfs rurfs rrufs rrufs fursr ufrsr frusr rfusr urfsr rufsr fusrr ufsrr fsurr sfurr usfrr sufrr frsur rfsur fsrur sfrur rsfur srfur ursfr rusfr usrfr surfr rsufr srufr fursr ufrsr frusr rfusr urfsr rufsr fusrr ufsrr fsurr sfurr usfrr sufrr frsur rfsur fsrur sfrur rsfur srfur ursfr rusfr usrfr surfr rsufr srufr frrsu rfrsu frrsu rfrsu rrfsu rrfsu frsru rfsru fsrru sfrru rsfru srfru frsru rfsru fsrru sfrru rsfru srfru rrsfu rrsfu rsrfu srrfu rsrfu srrfu urrsf rursf urrsf rursf rrusf rrusf ursrf rusrf usrrf surrf rsurf srurf ursrf rusrf usrrf surrf rsurf srurf rrsuf rrsuf rsruf srruf rsruf srruf
Note: these 'words' (valid or invalid) are all the permutations of the word furrs. These words are obtained by scrambling the letters in furrs.