ntsw tnsw nstw sntw tsnw stnw ntws tnws nwts wnts twns wtns nswt snwt nwst wnst swnt wsnt tswn stwn twsn wtsn swtn wstn
Note: these 'words' (valid or invalid) are all the permutations of the word ntsw. These words are obtained by scrambling the letters in ntsw.