import turtle,time def koch(size,n):     if n==0:         turtle.fd(size)     else:         for angle in [0,60,-120,60]:             turtle.left(angle)             koch(size/3,n-1) def main():     turtle.setup(600,600)     turtle.penup()     turtle.goto(-200,100)     turtle.pendown()     turtle.pensize(2)     level=3     koch(400,level)     turtle.right(120)     koch(400,level)     turtle.right(120)     koch(400, level)     # turtle.hideturtle()     time.sleep(3)     turtle.done main()