import Data.Bool (bool)
import Data.Char (isDigit)
import Data.List (splitAt)

main :: IO ()
main = do
    [a,_] <- readInts
    s <- getLine
    putStrLn $ solve a s

readInts :: IO [Int]
readInts = map read . words <$> getLine

solve :: Int -> String -> String
solve a = toAnswer . valid a

toAnswer :: Bool -> String
toAnswer = bool "No" "Yes"

valid :: Int -> String -> Bool
valid a s = all isDigit l && c == '-' && all isDigit r
  where
    (l,(c:r)) = splitAt a s
