Problem Statement

Takahashi is standing at the origin of a two-dimensional plane.

By taking one step, he can move to a point whose Euclidian distance from his current position is exactly $R$ (the coordinates of the destination of a move do not have to be integers). There is no other way to move.

Find the minimum number of steps Takahashi has to take before reaching $(X, Y)$.

We remind you that the Euclidian distance between points $(x_1,y_1)$ and $(x_2,y_2)$ is $\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$.

Constraints

• $1 \leq R \leq 10^5$
• $0 \leq X,Y \leq 10^5$
• $(X,Y) \neq (0,0)$
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

R X Y

Output

Print the minimum number of steps Takahashi has to take before reaching $(X, Y)$.