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 v5.12) (judge verdict: Accepted)

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.main = function (r) {
    return Math.pow(r, 2) * 3;
};
var exec = function () {
    var r = require('fs').readFileSync('/dev/stdin', 'UTF-8');
    var res = exports.main(Number(r));
    console.log(res);
};
exec();