#CODE = #B055
import turtle as t
t.tracer(200)
t.setup(1000,300)
t.setpos(100,-50)
t.bgcolor('black')
color=('blue','yellow')
for i in range(500):
    t.pencolor(color[i%2])
    t.circle(90,90)
    t.circle(i,90)
    t.circle(200,90)
t.done()