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 Ruby (2.3.3) (judge verdict: Wrong Answer)

        n = gets.to_i
        a = []
         
        n.times do
          a.push gets.to_i
        end
        m = a.max
         
        if a.count > 1
          n.times do
          	puts a.max
          end
        else
          n.times do |i|
            if a[i] == m
              a[i] = -1
              puts a.max
              a[i] = m
            else
              puts m
            end
          end
        end