<_description>
The "Rubik's Snake" puzzle. See also the "Rubik" and "Cube21" screen savers.
-http://en.wikipedia.org/wiki/Rubik%27s_Snake
+https://en.wikipedia.org/wiki/Rubik%27s_Snake
Written by Jamie Wilkinson, Andrew Bennetts, and Peter Aylett; 2002.
</_description>