nirls inrls nrils rnils irnls rinls nilrs inlrs nlirs lnirs ilnrs linrs nrlis rnlis nlris lnris rlnis lrnis irlns rilns ilrns lirns rlins lrins nirsl inrsl nrisl rnisl irnsl rinsl nisrl insrl nsirl snirl isnrl sinrl nrsil rnsil nsril snril rsnil srnil irsnl risnl isrnl sirnl rsinl srinl nilsr inlsr nlisr lnisr ilnsr linsr nislr inslr nsilr snilr isnlr sinlr nlsir lnsir nslir snlir lsnir slnir ilsnr lisnr islnr silnr lsinr slinr nrlsi rnlsi nlrsi lnrsi rlnsi lrnsi nrsli rnsli nsrli snrli rsnli srnli nlsri lnsri nslri snlri lsnri slnri rlsni lrsni rslni srlni lsrni slrni irlsn rilsn ilrsn lirsn rlisn lrisn irsln risln isrln sirln rsiln sriln ilsrn lisrn islrn silrn lsirn slirn rlsin lrsin rslin srlin lsrin slrin
Note: these 'words' (valid or invalid) are all the permutations of the word nirls. These words are obtained by scrambling the letters in nirls.