import           Data.Char

main :: IO ()
main = do
    [a, b] <- map read . words <$> getLine :: IO [Int]
    s <- getLine
    putStrLn $ if s !! (a+1) == '-'
                  && solve (take a s) (drop (a+1) s)
                  then "Yes"
                  else "No"

solve = flip ((.).(&&). p) p
    where
      p = all isDigit
