FORWARD = (0, 1)
RIGHT_FORWARD = (1, 1)
RIGHT = (1, 0)
RIGHT_BACKWARD = (1, -1)
BACKWARD = (0, -1)
LEFT_BACKWARD = (-1, -1)
LEFT = (-1, 0)
LEFT_FORWARD = (-1, 1)

MOVE_FORWARD = 'move forward'
TURN_RIGHT = 'turn right 90 degrees'
