Axis of symmetry of the quadrilateral

Given the coordinates of the successive vertices of a convex quadrilateral. How many axes of symmetry does this figure?

Input

In one line contains 8 digitsx₁, y₁, x₂, y₂, x₃, y₃, x₄, y₄ – coordinates of the vertices of a quadrilateral.

-50 ≤ x₁, y₁, x₂, y₂, x₃, y₃, x₄, y₄ ≤ 50

Output

One number - the number of axes of symmetry.