Problem:
Score : 200 points

Problem Statement

The postal code in Atcoder Kingdom is A+B+1 characters long, its (A+1)-th character is a hyphen -, and the other characters are digits from 0 through 9.

You are given a string S. Determine whether it follows the postal code format in Atcoder Kingdom.

Constraints

1≤A,B≤5

|S|=A+B+1

S consists of - and digits from 0 through 9.

Input

Input is given from Standard Input in the following format:

A B
S

Output

Print Yes if S follows the postal code format in AtCoder Kingdom; print No otherwise.

Sample Input 1

3 4
269-6650

Sample Output 1

Yes

The (A+1)-th character of S is -, and the other characters are digits from 0 through 9, so it follows the format.

Sample Input 2

1 1
---

Sample Output 2

No

S contains unnecessary -s other than the (A+1)-th character, so it does not follow the format.

Sample Input 3

1 2
7444

Sample Output 3

No

Solution in Haskell (GHC 8.8.3) (judge verdict: Accepted)

{-# LANGUAGE Strict #-}
import           Data.Char (isDigit)

main :: IO ()
main = do
  [a, b] <- map read . words <$> getLine
  s <- getLine
  putStrLn $ if solve a b s then "Yes" else "No"

solve :: Int -> Int -> String -> Bool
solve a _ s = all isDigit xs && y == '-' && all isDigit ys
  where (xs, y:ys) = splitAt a s