Angle

There are two points in the plane, so we can draw two segments between the original and each of them respectively. Calculate the angle between the two segments.

The angel should be a radian and less than (3.1415926…). Be careful, it's angle, not the cute angel.

Input

The first line contains a single integer T, indicating the number of test cases. Each test case begins contains four integers X_a, Y_a, X_b, Y_b (-10000 ≤ X_a, X_b, Y_a, Y_b ≤ 10000), indicating the coordinates of the two points. You can assume both of them won't be the original point.

Output

For each case, output the angle rounded to three fractional digits.

Examples