# Problem 208: Robot Walks
A robot moves in a series of one-fifth circular arcs (72°), with a free
choice of a clockwise or an anticlockwise arc for each step, but no
turning on the spot. One of 70932 possible closed paths of 25 arcs
starting northward is Given that the robot starts facing North, how many
journeys of 70 arcs in length can it take that return it, after the
final arc, to its starting position? (Any arc may be traversed multiple
times.)