from microbit import*

while True:
  x=-1
  y=-1
  for i in range (5):
    x = x + 1 
    y = y + 1
    display.set_pixel(x,y,9)
    sleep(500)
  x=5
  y=-1
  for i in range (5):
    x = x = x -1
    y = y + 1
    display.set_pixel(x,y,9)
    sleep(500)