lisps ilsps lsips slips islps silps lipss ilpss lpiss pliss iplss pilss lspis slpis lpsis plsis splis pslis ispls sipls ipsls pisls spils psils lissp ilssp lsisp slisp islsp silsp lissp ilssp lsisp slisp islsp silsp lssip slsip lssip slsip sslip sslip isslp sislp isslp sislp ssilp ssilp lipss ilpss lpiss pliss iplss pilss lisps ilsps lsips slips islps silps lpsis plsis lspis slpis pslis splis ipsls pisls ispls sipls psils spils lspsi slpsi lpssi plssi splsi pslsi lsspi slspi lsspi slspi sslpi sslpi lpssi plssi lspsi slpsi pslsi splsi spsli pssli sspli sspli pssli spsli ispsl sipsl ipssl pissl spisl psisl isspl sispl isspl sispl ssipl ssipl ipssl pissl ispsl sipsl psisl spisl spsil pssil sspil sspil pssil spsil
Note: these 'words' (valid or invalid) are all the permutations of the word lisps. These words are obtained by scrambling the letters in lisps.