ohtsl hotsl othsl tohsl htosl thosl ohstl hostl oshtl sohtl hsotl shotl otshl toshl osthl sothl tsohl stohl htsol thsol hstol shtol tshol sthol ohtls hotls othls tohls htols thols ohlts holts olhts lohts hlots lhots otlhs tolhs olths loths tlohs ltohs htlos thlos hltos lhtos tlhos lthos ohslt hoslt oshlt sohlt hsolt sholt ohlst holst olhst lohst hlost lhost oslht solht olsht losht sloht lsoht hslot shlot hlsot lhsot slhot lshot otslh toslh ostlh sotlh tsolh stolh otlsh tolsh oltsh lotsh tlosh ltosh oslth solth olsth losth sloth lsoth tsloh stloh tlsoh ltsoh sltoh lstoh htslo thslo hstlo shtlo tshlo sthlo htlso thlso hltso lhtso tlhso lthso hslto shlto hlsto lhsto slhto lshto tslho stlho tlsho ltsho sltho lstho
Note: these 'words' (valid or invalid) are all the permutations of the word ohtsl. These words are obtained by scrambling the letters in ohtsl.