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: Runtime Error)

n=int(input())
x=[]
for i in range(n):
  x.append(int(input()))
cnt = [0] * n
for i in range(n):
  for j in range(n):
    if i is not j and cnt[i] < x[j]:
      cnt[i]=x[j]
for i in range(n):
  print(cnt[i])