main = do
  [a, _] <- map read . words <$> getLine
  s <- getLine
  putStr $ solve a s

solve (-1) [] = "Yes"
solve (-1) (x:xs)
  | x `elem` [0..9] = solve (-1) xs
  | otherwise = "No"
solve 0 (x:xs)
  | x == '-' = solve (-1) xs
  | otherwise = "No"
solve a (x:xs)
  | x `elem` [0..9] = solve (a - 1) xs
  | otherwise = "No"
