fouth ofuth fuoth ufoth oufth uofth fotuh oftuh ftouh tfouh otfuh tofuh futoh uftoh ftuoh tfuoh utfoh tufoh outfh uotfh otufh toufh utofh tuofh fouht ofuht fuoht ufoht oufht uofht fohut ofhut fhout hfout ohfut hofut fuhot ufhot fhuot hfuot uhfot hufot ouhft uohft ohuft houft uhoft huoft fothu ofthu ftohu tfohu otfhu tofhu fohtu ofhtu fhotu hfotu ohftu hoftu fthou tfhou fhtou hftou thfou htfou othfu tohfu ohtfu hotfu thofu htofu futho uftho ftuho tfuho utfho tufho fuhto ufhto fhuto hfuto uhfto hufto fthuo tfhuo fhtuo hftuo thfuo htfuo uthfo tuhfo uhtfo hutfo thufo htufo outhf uothf otuhf touhf utohf tuohf ouhtf uohtf ohutf houtf uhotf huotf othuf tohuf ohtuf hotuf thouf htouf uthof tuhof uhtof hutof thuof htuof
Note: these 'words' (valid or invalid) are all the permutations of the word fouth. These words are obtained by scrambling the letters in fouth.