A blueprint places two axis-aligned rectangular rooms on an integer grid. Each rectangle is given by its lower-left corner (x1, y1) and its upper-right corner (x2, y2) with x1 < x2 and y1 < y2. Print the area of the region covered by both rectangles at once. If they do not overlap, or only touch along an edge or corner, the overlapping area is 0.
Input format
Line 1: four integers x1 y1 x2 y2 for the first rectangle.
Line 2: four integers x1 y1 x2 y2 for the second rectangle.
Output format
A single integer: the area of the intersection.
Constraints
- -1000000000 <= x1 < x2 <= 1000000000
- -1000000000 <= y1 < y2 <= 1000000000