# Area of Two Circles' Intersection

Time Limit: 2 seconds

Memory Limit: 256 megabytes

## Description

You are given two circles. Find the area of their intersection.

## Input

The first line contains three integers x1, y1, r1 ( - 109 ≤ x1, y1 ≤ 109, 1 ≤ r1 ≤ 109) — the position of the center and the radius of the first circle.

The second line contains three integers x2, y2, r2 ( - 109 ≤ x2, y2 ≤ 109, 1 ≤ r2 ≤ 109) — the position of the center and the radius of the second circle.

## Output

Print the area of the intersection of the circles. The answer will be considered correct if the absolute or relative error doesn't exceed 10 - 6.

## Sample Input

Input0 0 46 0 4Output7.25298806364175601379Input0 0 511 0 5Output0.00000000000000000000

## Sample Output

None

None

None