import           Control.Monad
import           Data.Array
import qualified Data.ByteString.Char8         as BS
import           Data.List
import           Data.Maybe
import           Data.Ord

readInts :: IO [Int]
readInts = map (fst . fromJust . BS.readInt) . BS.words <$> BS.getLine

main :: IO ()
main = do
  (a : p : _) <- readInts
  print $ solve a p

solve :: Integral a => a -> a -> a
solve a p = (a * 3 + p) `div` 2
