F - Rectangles

Time Limit: 1 sec
Memory Limit: 16MB

This problem has no story. You just have to find the common area of all rectangles.

INPUT:

The first line contains integer N (1 <= N <= 1000). It is the number of tests. Each test described by number of rectangles M (1 <= M <= 30). Next N lines contain 4 integers: X1 Y1 X2 Y2 (-10000 <= X1; Y2; X2; Y2 <= 10000). Each rectangle is described by 2 points: lower left and upper right corners. All rectangle sides are parallel to Ox or Oy axes.

OUTPUT:

For each test case out line formatter like this: "Case i: a". Where "i" is a test number, and "a" is an area that belongs to all rectangles.

SAMPLE INPUT:

1
4
0 0 10 10
-1 -1 2 2
-10 0 2 100
-10 -10 10 10

SAMPLE OUTPUT:

Case 1: 4

Problem setters: Aleksej Viktorchik, Leonid Shishlo.
Huge Easy Contest #1