import Data.Char

main = do
  (a:b:_) <- getLine >>= return . (map read) . words :: IO [Int]
  p <- getLine

  putStrLn $ func p a
  
  where
    func xs t = if h=='-' && isNum a && isNum b then "Yes" else "No"
      where
        (a,b') = splitAt t xs
        h = head b'
        b = tail b'

    isNum [] = False
    isNum xs = all (\x -> (ord x) >= (ord '0') && (ord x) <= (ord '9')) xs
