-- Your code here!
import Control.Monad
import Data.Maybe
import qualified Data.ByteString.Char8 as BS
import Data.List
 
readInt = fst . fromJust . BS.readInt
readIntList = map readInt . BS.words
getInt = readInt <$> BS.getLine
getIntList = readIntList <$> BS.getLine

main = do
    a <- getInt
    
    print $ 3*a*a