title 
Dragon Curve

description
Given a string of 2^n -1 0's, produces
a sequence of L's and R's corresponding
to the dragon curve of length 2^n - 1.
Rejects input if the number of 0's
is not a power of 2, minus 1,

vertices
0 L 0.1 0.5 
1 R 0.3 0.25
2 R 0.6 0.25
3 R 0.6 0.75
4 R 0.3 0.75
5 H 0.9 0.25
6 N 0.45 0.5

edges
0 1 # #
1 2 0 L
1 6 # #
2 3 0 0
2 5 # #
3 4 0 R
3 6 # #
4 0 # #
4 1 0 0


tapes
[0] 0 0
[0] 0 0 0 0 0 0
[0] 0 0 0 0 0 0 0 0 0 0 0 0 0 0