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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>)
{
    val r = readInt()

    println(3 * r *r)

}


// Read an integer
// Usage: val a = readInt()
private fun readInt() = readLine()!!.toInt()

// Read N integers separated by " "
// Usage: val (a, b, c) = readNInts()
private fun readNInts() = readLine()!!.split(" ").map(String::toInt)

// Read a string
// Usage: val a = readString()
private fun readString() = readLine()!!