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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