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.

Examples

Input

4


Output

48


Input

15


Output

675


Input

80


Output

19200
import sys
from collections import deque
import copy
import math
def get_read_func(fileobject):
    if fileobject == None :
        return raw_input
    else:
        return fileobject.readline



def main():
    if len(sys.argv) > 1:
        f = open(sys.argv[1])
    else:
        f = None
    read_func = get_read_func(f);
    input_raw = read_func().strip().split()
    [r] = [int(input_raw[0])]
    print 3 * r * r

if __name__ == '__main__':
    main()
