hwyl whyl hywl yhwl wyhl ywhl hwly whly hlwy lhwy wlhy lwhy hylw yhlw hlyw lhyw ylhw lyhw wylh ywlh wlyh lwyh ylwh lywh
Note: these 'words' (valid or invalid) are all the permutations of the word hwyl. These words are obtained by scrambling the letters in hwyl.