rusks ursks rsuks sruks usrks surks rukss urkss rkuss kruss ukrss kurss rskus srkus rksus krsus skrus ksrus uskrs sukrs uksrs kusrs skurs ksurs russk urssk rsusk srusk usrsk sursk russk urssk rsusk srusk usrsk sursk rssuk srsuk rssuk srsuk ssruk ssruk ussrk susrk ussrk susrk ssurk ssurk rukss urkss rkuss kruss ukrss kurss rusks ursks rsuks sruks usrks surks rksus krsus rskus srkus ksrus skrus uksrs kusrs uskrs sukrs ksurs skurs rsksu srksu rkssu krssu skrsu ksrsu rssku srsku rssku srsku ssrku ssrku rkssu krssu rsksu srksu ksrsu skrsu sksru kssru sskru sskru kssru sksru usksr suksr ukssr kussr skusr ksusr usskr suskr usskr suskr ssukr ssukr ukssr kussr usksr suksr ksusr skusr sksur kssur sskur sskur kssur sksur
Note: these 'words' (valid or invalid) are all the permutations of the word rusks. These words are obtained by scrambling the letters in rusks.