Two charges $$+q$$ and $$-q$$ are separated by a distance $$d=50~\mbox{cm}$$. The electric field lines for this system form the the well-known pattern showed in the figure below. Consider two lines $$L_{1}$$ and $$L_{2}$$ lying on the same plane and leaving the positive charge at $$\alpha=\pm 45^{\circ}.$$ What is the maximum distance $$D$$ between the lines in centimeters.