obxo boxo oxbo xobo bxoo xboo obox boox oobx oobx boox obox oxob xoob ooxb ooxb xoob oxob bxoo xboo boxo obxo xobo oxbo
Note: these 'words' (valid or invalid) are all the permutations of the word obxo. These words are obtained by scrambling the letters in obxo.