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.