It appears that we've focused on mathematics puzzles in the early part of this week, so I'll give the word-game fans their comeuppance. And I'll do it with only two letters of the alphabet. Today's Brain Game:

What's the longest non-hyphenated
English word that contains only
two different letters of the alphabet?

Here are three possible answers. Please feel free to comment with any additional ones that you may find.

POSSIBLE ANSWERS: Six-letter words that meet the requirement include booboo, deeded, and muumuu. Some dictionaries hyphenate "booboo" and "muumuu" while others do not. So we'll say that deeded is the "best" word we can find. Can you do better?