From the point $$(-1, -1)$$, two rays are sent making angle  of $$45°$$ with the line $$x + y = 0$$. The rays get reflected from the mirror $$x + 2y = 1$$. If the equations of the reflected rays are $$ax + by = 9$$ and $$cx + dy = 7$$,$$a,b,c,d \in \mathbb{Z}$$ thenthe value of  $$ad + bc$$ is :