{-# LANGUAGE FlexibleContexts, OverloadedStrings #-}
import Control.Applicative
import Control.Monad
import qualified Data.ByteString.Char8 as B
import Data.Maybe (fromJust)
import Text.Printf
import Debug.Trace

--  a = nb + (n+1)c
--  n = (a-c)/(b+c)
main = do
  [a,b,c] <- getInts
  print $ (a-c) `div` (b+c)


-- util
getInts :: IO [Int]
getInts = map (fst . fromJust . B.readInt) . B.words <$> B.getLine

