risus irsus rsius srius isrus sirus riuss iruss ruiss uriss iurss uirss rsuis sruis rusis ursis suris usris isurs siurs iusrs uisrs suirs usirs rissu irssu rsisu srisu isrsu sirsu rissu irssu rsisu srisu isrsu sirsu rssiu srsiu rssiu srsiu ssriu ssriu issru sisru issru sisru ssiru ssiru riuss iruss ruiss uriss iurss uirss risus irsus rsius srius isrus sirus rusis ursis rsuis sruis usris suris iusrs uisrs isurs siurs usirs suirs rsusi srusi russi urssi sursi usrsi rssui srsui rssui srsui ssrui ssrui russi urssi rsusi srusi usrsi sursi susri ussri ssuri ssuri ussri susri isusr siusr iussr uissr suisr usisr issur sisur issur sisur ssiur ssiur iussr uissr isusr siusr usisr suisr susir ussir ssuir ssuir ussir susir
Note: these 'words' (valid or invalid) are all the permutations of the word risus. These words are obtained by scrambling the letters in risus.