You are given four points $A,B,C$ and $\mbox{D}$ in a 3-dimensional Cartesian coordinate system. You are required to print the angle between the plane made by the points $A,B,C$ and $B,C,D$ in degrees(not radians). Let the angle be $\textit{PHI}$.

$\textit{Cos}(PHI)=(X.Y)/|X||Y|$ where $X=\textit{AB}$ x $\mbox{BC}$ and $\textbf{Y}=\textit{BC}$ x $\boldsymbol{\mathrm{CD}}$.

Here, $X.Y$ means the dot product of $\mbox{X}$ and $\mathbf{Y}$, and $\boldsymbol{AB}$ x $\mbox{BC}$ means the cross product of vectors $\boldsymbol{AB}$ and $\mbox{BC}$. Also, $\textit{AB}=B-A$.

Input Format

One line of input containing the space separated floating number values of the $X,Y$ and $\mbox{z}$ coordinates of a point.

Output Format

Output the angle correct up to two decimal places.

Sample Input

0 4 5
1 7 6
0 5 9
1 7 2

Sample Output

8.19

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