Problem:
Score : 100 points

Problem Statement

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.

Sample Input 1

4

Sample Output 1

48

The area of the regular dodecagon is 3 \times 4^2 = 48.

Sample Input 2

15

Sample Output 2

675

Sample Input 3

80

Sample Output 3

19200

Solution in JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

function main(input) {
   input = input.trim();
  const a = input.split(" ").map(Number);

  console.log(3*a[0]*a[0]);
  
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));