Problem Statement

On the coordinate plane, you first place one piece, either a rook or a bishop, at the origin $(0,0)$.

The range of movement of each piece is as follows.

• Rook: From the current position $(x, y)$, it can move in one move to $(x + k, y)$ or $(x, y + k)$ for any chosen real number $ k $.

• Bishop: From the current position $(x, y)$, it can move in one move to $(x + k, y + k)$ or $(x - k, y + k)$ for any chosen real number $ k $.

Find the minimum number of moves required to move the initially placed piece to the goal position $(G_x, G_y)$, when you choose the appropriate piece.

Constraints

• $-10^9 \leq G_x \leq 10^9$
  
• $-10^9 \leq G_y \leq 10^9$
• All inputs are given as integers.

Input

$G_x$ $G_y$

Output

Find the minimum number of moves required to move the placed piece to the goal position $(G_x, G_y)$, when you choose the appropriate piece.

Sample

1 1

1

2 3

2