import Data.Bits
import Data.List
import Control.Monad
import qualified Data.Vector.Unboxed as V
import qualified Data.Vector.Unboxed.Mutable as VM
import Data.Array
import Data.Array.MArray
import Data.Array.ST
import Control.Monad.ST
import Data.Maybe (fromMaybe)
import qualified Data.ByteString.Lazy.Char8 as B
import Debug.Trace


main :: IO ()
main = do
  [a,b,c] <- map read.words <$> getLine :: IO [Int]
  print $ max 0 $ b+c-a