3405：Convex hull

There are M circles (0 ≤ M ≤ 100) on a plane. Some circles can have zero radius. The task is to calculate the area of minimum convex domain containing all the circles.

The input contains the description of one test including:

• a line with value M;
• M lines; every line contains coordinates of the center and the radius for one circle. These are real numbers separated by spaces.

The output contains a single line with the result given with accuracy 10^-4.