import turtle
pen = turtle.Turtle
def sq(a):
  for i in range(4):
    pen.color(colors[i%4])
    pen.forward(a)
    pen.left(90)

colors = ['red','brown','green','blue']
pen.speed(100)

dlina = 100
for i in range(50):
  
  sq(dlina)
  pen.right(10)
  dlina = dlina+1