import itertools

import fractions

def main():

  r = int(eval(input()))

  print((3 * (r**2)))

  

if __name__ == '__main__':

  main()
#from statistics import median

#import collections

#aa = collections.Counter(a) # list to list || .most_common(2)で最大の2個とりだせるお a[0][0]

#from fractions import gcd

#from itertools import combinations # (string,3) 3回

#from collections import deque

from collections import defaultdict

#import bisect

#

#    d = m - k[i] - k[j]

#    if kk[bisect.bisect_right(kk,d) - 1] == d:

#

#

#

# pythonで無理なときは、pypyでやると正解するかも！！

#

#



import sys

sys.setrecursionlimit(10000000)

mod = 10**9 + 7

#mod = 9982443453

def readInts():

  return list(map(int,input().split()))

def I():

  return int(eval(input()))

r = I()

print((3*r**2))

import itertools
import fractions


def main():
    r = int(eval(input()))
    print((3 * (r**2)))


if __name__ == "__main__":
    main()

# from statistics import median
# import collections
# aa = collections.Counter(a) # list to list || .most_common(2)で最大の2個とりだせるお a[0][0]
# from fractions import gcd
# from itertools import combinations # (string,3) 3回
# from collections import deque
from collections import defaultdict

# import bisect
#
#    d = m - k[i] - k[j]
#    if kk[bisect.bisect_right(kk,d) - 1] == d:
#
#
#
# pythonで無理なときは、pypyでやると正解するかも！！
#
#
import sys

sys.setrecursionlimit(10000000)
mod = 10**9 + 7
# mod = 9982443453
def readInts():
    return list(map(int, input().split()))


def I():
    return int(eval(input()))


r = I()
print((3 * r**2))

-import itertools -import fractions +# from statistics import median +# import collections +# aa = collections.Counter(a) # list to list || .most_common(2)で最大の2個とりだせるお a[0][0] +# from fractions import gcd +# from itertools import combinations # (string,3) 3回 +# from collections import deque +from collections import defaultdict + +# import bisect +# +#    d = m - k[i] - k[j] +#    if kk[bisect.bisect_right(kk,d) - 1] == d: +# +# +# +# pythonで無理なときは、pypyでやると正解するかも！！ +# +# +import sys + +sys.setrecursionlimit(10000000) +mod = 10**9 + 7 +# mod = 9982443453 +def readInts(): +    return list(map(int, input().split())) -def main(): -    r = int(eval(input())) -    print((3 * (r**2))) +def I(): +    return int(eval(input())) -if __name__ == "__main__": -    main() +r = I() +print((3 * r**2))