E. Air Moped
time limit per test
5 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

A renowned airbender Tang invents a technique he calls the "Air Moped", where he spins up a perfect sphere and can ride on it. The bigger the sphere, the easier it is to ride on it and the faster it can go.

A student of his is geometrically inclined and wants to know how many lattice points (i.e. how many points $$$(x, y, z)$$$ where $$$x$$$, $$$y$$$ and $$$z$$$ are integers) are on the surface of some air moped that is created. Can you help him?

Input

One integer $$$1 \leq R \leq 7500$$$, the radius of the air moped.

Output

One integer $$$N$$$ denoting the number of integer coordinate points on the surface of the air moped.

Examples
Input
1
Output
6
Input
2
Output
6