Problems
Combined rectangles
Combined rectangles
Combining rectangles is much easier when its sides are parallel to the coordinate axes. Find the total area covered by a given set of rectangles.
Input
The first line contains the number of rectangles n (2 ≤ n ≤ 3). Each of the next n lines contains coordinates of opposite corners of rectangle in format: x1 y1 x2 y2. The coordinates are integers in the range [-109, 109].
The rectangles can be degenerated.
Output
Print the total area covered by the given set of rectangles, rounded to the nearest integer.
Input example #1
2 0 0 10 10 20 5 5 20
Output example #1
300
Input example #2
2 0 0 10 10 20 15 15 20
Output example #2
125
Input example #3
2 0 0 10 10 3 5 5 3
Output example #3
100
Input example #4
3 0 0 4 4 1 1 5 2 1 1 2 5
Output example #4
18