Valera the horse lives on a plane. The Cartesian coordinate system is defined on this plane. Also an infinite spiral is painted on the plane. The spiral consists of segments: $[(0, 0), (1, 0)]$, $[(1, 0), (1, 1)]$, $[(1, 1), ( - 1, 1)]$, $[( - 1, 1), ( - 1,  - 1)]$, $[( - 1,  - 1), (2,  - 1)]$, $[(2,  - 1), (2, 2)]$ and so on. Thus, this infinite spiral passes through each integer point of the plane.

Valera the horse lives on the plane at coordinates $(0, 0)$. He wants to walk along the spiral to point $(*x*, *y*)$. Valera the horse has four legs, so he finds turning very difficult. Count how many times he will have to turn if he goes along a spiral from point $(0, 0)$ to point $(*x*, *y*)$.

Input

The first line contains two space-separated integers $*x*$ and $*y*$ $(|*x*|, |*y*| ≤ 100)$.

Output

Print a single integer, showing how many times Valera has to turn.