from turtle import *
from random import *
speed()
pensize(12)

def rect(size):
  for count in range(4):
    forward(size)
    right(90)
    if count == 1 and size > 30:
      rect(size/2)

for count in range(10):
  color('#%06x' % randint(0, 2**24 - 1))  #muss man nicht im Detail verstehen
  rect(100)
  right(36)