p02969 AtCoder Beginner Contest 134 - Dodecagon_6226
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 sc = new Scanner(System.in);
		int n = sc.nextInt();

		int a = 3 * n * n;



		System.out.println(a);

		sc.close();
	}
}
