If the point \( (3,4,5) \) divides the line segment joining the points \( (1,2,3) \) and \( (4,5,6) \) in the ratio \( 2:1 \), then the point which divides the line segment joining the points \( (3,4,5) \) and \( (1,2,3) \) in the ratio \( -1:2 \) is: