eolymp
bolt
Try our new interface for solving problems
Problems

Green spot - 2

Green spot - 2

Time limit 1 second
Memory limit 64 MiB

Two projectors of the round form form on a wall two spots, one - blue, and the second – yellow color. To define the area of a spot of green color which will turn out at imposing two spots.

Input data

In the first line coordinates of the center of one spot contain: X_1, Y_1 and its radius R_1, and in the second – coordinates of the center of second spot X_2, Y_2 and its radius R_2. (|X_i|, |Y_i|, R_i <= 10^6)

Output data

In one line a singular: the required area of a green spot deduced with accuracy of 3 signs after a decimal point, received by rules of mathematical calculations.

Examples

Input example #1
0 0 2
2 2 1
Output example #1
0.108