e-olymp
Problems

The area of a pyramid

The area of a pyramid

A triangular pyramid is given the coordinates of its vertices A(x1; y1; z1), B(x2; y2; z2), C(x3; y3; z3), S(x4; y4; z4). Find the total surface area of the pyramid.

Input

In four lines given the coordinates x, y and z of the pyramid vertices. All input data are integers, not exceeding 100 by absolute value.

Output

Print the total surface area of the pyramid, rounded to the nearest tenth.

Time limit 1 second
Memory limit 128 MiB
Input example #1
-3 0 0
0 6 0
3 0 0
0 2 5
Output example #1
69.8