def calculateBallRegion(ballCoordinate, robotCoordinate) -> int:
  """ Ball region is the region of the ball according to robot.
      We assumed the robot as origin of coordinate system.

  Args:
      ballCoordinate (list): x, y, z coordinates of the ball.
      robotCoordinate (list): x, y coordinates of the robot.

  Returns:
      int: 1 = top-right, 2 = top-left, 3 = bottom-left, 4 = bottom-right
  """
  ballRegion = 0
  # Find the location of the ball according to the robot.
  if ballCoordinate[0] > robotCoordinate[0]:
    if ballCoordinate[1] > robotCoordinate[1]:
      ballRegion = 1
    else:
      ballRegion = 4
  else:
    if ballCoordinate[1] > robotCoordinate[1]:
      ballRegion = 2
    else:
      ballRegion = 3

  # print(ballRegion)

  return ballRegion