{-# LANGUAGE TypeApplications #-}
import qualified Data.ByteString.Char8 as BS
import qualified Data.ByteString.Char8 as B
import Data.Maybe
import Data.List
import Control.Monad

toInt :: String -> Int
toInt = read

main :: IO ()
main = do
  l <- words <$> getLine
  let a = toInt $ l !! 0
  let b = toInt $ [x | x <- l !! 1, not (elem x ".")]
  print $ div (a * b) 100