The 35 hexominoes shown above (you can use a Sextillions set without the duplicate piece) can form a fully enclosed long passage no wider than one square at any point. The passage can twist and turn in any direction and even loop back on itself without intersecting.

What is the longest passage, closed at both ends, that you can make with the 35 pieces? The example below shows a passage of 20 units using only 11 pieces. Can you beat our best solution of 138 units, using all 35 hexominoes? Notice how the surrounding pieces must be connected on at least one full edge, not merely corners.

We will award a prize to the best solution longer than 138 units received by January 1, 2005. To enter this contest, email your name, address and solution in picture or text form to kadon@gamepuzzles.com. Use letters and numbers to designate the pieces and a symbol to designate the passage. Or you may snailmail your drawing on paper to:

Kadon Enterprises, Inc.
1227 Lorene Drive, Suite 16
Pasadena, MD 21122