ypuy pyuy yupy uypy puyy upyy ypyu pyyu yypu yypu pyyu ypyu yuyp uyyp yyup yyup uyyp yuyp puyy upyy pyuy ypuy uypy yupy
Note: these 'words' (valid or invalid) are all the permutations of the word ypuy. These words are obtained by scrambling the letters in ypuy.