# Problem 8B
#
# Running the 400m intermediate hurdles
#
# exploding

import math

g.paper(100)
g.pen(0)
g.norefresh()

def spiraller(xc, yc, radius, turns, points, length):
    canvas = []
    for n in range(points):
        x1 = xc + float(n)/points*radius*math.cos(turns*float(n)/points)
        y1 = yc + float(n)/points*radius*math.sin(turns*float(n)/points)
        canvas.append((int(x1),int(y1)))
        if n % 2 == 0:
                g.line(canvas[n-1][0],canvas[n-1][1],canvas[n][0],canvas[n][1])
        g.line(int(x1-length),int(y1-length),int(x1),int(y1))

maxturn = 100
k = []
for n in range(maxturn):
  k.append(maxturn-n)
  
while 1:
  for n in range(maxturn):
          spiraller(50,50,70,n,80,3)
          g.refresh()
          g.paper(100)
  for n in k:
          spiraller(50,50,70,n,80,3)
          g.refresh()
          g.paper(100)