rosts orsts rsots srots osrts sorts rotss ortss rtoss tross otrss torss rstos srtos rtsos trsos stros tsros ostrs sotrs otsrs tosrs stors tsors rosst orsst rsost srost osrst sorst rosst orsst rsost srost osrst sorst rssot srsot rssot srsot ssrot ssrot ossrt sosrt ossrt sosrt ssort ssort rotss ortss rtoss tross otrss torss rosts orsts rsots srots osrts sorts rtsos trsos rstos srtos tsros stros otsrs tosrs ostrs sotrs tsors stors rstso srtso rtsso trsso strso tsrso rssto srsto rssto srsto ssrto ssrto rtsso trsso rstso srtso tsrso strso stsro tssro sstro sstro tssro stsro ostsr sotsr otssr tossr stosr tsosr osstr sostr osstr sostr ssotr ssotr otssr tossr ostsr sotsr tsosr stosr stsor tssor sstor sstor tssor stsor
Note: these 'words' (valid or invalid) are all the permutations of the word rosts. These words are obtained by scrambling the letters in rosts.