import           Data.Char

main :: IO ()
main = do
    [a,b] <- fmap read . words <$> getLine :: IO [Int]
    s <- init <$> getLine
    print $ solve (a,b) s

solve :: (Int,Int) -> String -> String
solve (a,b) s   | length s /= a + b + 1 = "No"
                | s !! a == '-' = solve' (take a s) (drop (a+1) s)
                | otherwise = "No"

solve' :: String -> String -> String
solve' a b = if chk a && chk b then "Yes" else "No" where
    chk ls = and $ isDigit <$> ls
