The area of a pyramid

A triangular pyramid is given the coordinates of its vertices A(x[1]; y[1]; z[1]), B(x[2]; y[2]; z[2]), C(x[3]; y[3]; z[3]), S(x[4]; y[4]; z[4]). 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.

Examples