xbay bxay xaby axby baxy abxy xbya bxya xyba yxba byxa ybxa xayb axyb xyab yxab ayxb yaxb bayx abyx byax ybax aybx yabx
Note: these 'words' (valid or invalid) are all the permutations of the word xbay. These words are obtained by scrambling the letters in xbay.