It is known that the area of a regular dodecagon inscribed in a circle of radius a is 3a^2.

Given an integer r, find the area of a regular dodecagon inscribed in a circle of radius r.

Constraints

* 1 \leq r \leq 100
* r is an integer.

Input

Input is given from Standard Input in the following format:


r


Output

Print an integer representing the area of the regular dodecagon.

Examples

Input

4


Output

48


Input

15


Output

675


Input

80


Output

19200
import java.util.Scanner;
public class Main
{
public static void main(String args[])
{
  Scanner in=new Scanner(System.in);
  int n=in.nextInt();
  System.out.println(3*n*n);
}
}
