A common operation in computer graphics is to compute the intersection of two objects. For this problem, you need to compute the intersection of a set of rectangles that are to be drawn to the screen.
Input begins with a line containing an integer $1 \le c \le 100$ indicating the number of test cases that follow. Each test case begins with a line with the number of rectangles $1 \le n \le 100$, followed by $n$ lines denoting coordinates left, top, right, and bottom. Coordinates are all integers, representing pixels, in the range $[0, 10\, 000]$. Top and right are positive directions.
For each case, print the area of the intersection of all the given rectangles. The area of any one rectangle is its width (right-left) times its height (top-bottom).
|Sample Input 1||Sample Output 1|
2 3 0 7 8 0 3 7 7 1 5 10 9 4 2 1 2 2 1 0 3 3 0