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 Python (3.4.3) (judge verdict: Accepted)

import sys

#+++++
		
def main():
	a = int(input())
	print(3*a*a)
	
	
#+++++

if __name__ == "__main__":
	if sys.platform =='ios':
		sys.stdin=open('inputFile.txt')
	else:
		input = sys.stdin.readline
			
	ret = main()
	if ret is not None:
		print(ret)