CF107E.Darts

The first line of input contains integer $n$ ( $1<=n<=500$ ) — the number of photos on the wall. Then follow $n$ lines describing the photos, each containing $8$ single-space-separated integers (coordinates of $4$ vertices): $x_{1}$ , $y_{1}$ , $x_{2}$ , $y_{2}$ , $x_{3}$ , $y_{3}$ , $x_{4}$ , $y_{4}$ . Each photo is a rectangle with a nonzero area. The coordinates are integers, not exceeding $10^{4}$ by absolute value. The coordinates of the rectangle are given in either clockwise or counterclockwise order.

Print the expected score of the throw. The answer will be accepted if it has absolute or relative error not exceeding $10^{-6}$ .

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