
The Scratch Cat wants to become rich by selling paintings, but he can't draw or paint well with his nonexistent paws. He decided to take a shortcut by creating his art digitally and printing them. Unfortunately, he only remembers how to use the circle tool on the Scratch Costume Editor™. He doesn't remember how to change the colour of his shapes either. The circle tool allows him to create filled circles with any radius and position.
He believes that creating a plain mashup of circles is not creative enough, so he comes up with a genius solution. He will create "donuts" (annuli) instead of circles. The Scratch Cat's annuli have radius
The Scratch Cat creates forces asks you to help!
Constraints
Subtask 1 [20%]
All
Subtask 2 [80%]
No additional constraints.
Input Specification
The first line will contain an integer
The next
Output Specification
Output the cost of ink used, which is a dollar per
Any answer within an absolute error of
Sample Input 1
1
3 3 0 2
Sample Output 1
1.2566
Explanation 1
This annulus is centred at
Sample Input 2
1
5 5 2 4
Sample Output 2
3.7699
Explanation 2
This annulus is centred at
Sample Input 3
2
0 2 6 7
9 0 6 7
Sample Output 3
7.9677
Explanation 3
It can be proven that the area of these
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