output_description: Print `Yes` if S follows the postal code format in AtCoder Kingdom; print `No`
  otherwise.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B
      S
attempt:     A, B = map(int, input().split())
      S = input()
      C = "1234567890"
      for i in range(len(S)):
          if i == A:
              if S[i] == "-":
                  continue
              else:
                  print("No")
                  exit()
          else:
              if S[i] in C:
                  continue
              else:
                  print("No")
                  exit()
      print("Yes")
      exit()
  resolve()
problem_description: 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.
samples: [{"input": "3 4\n    269-6650", "output": "Yes\n    \n\nThe (A+1)-th character of S is `-`, and the other characters are digits from\n`0` through `9`, so it follows the format.\n\n* * *"}, {"input": "1 1\n    ---", "output": "No\n    \n\nS contains unnecessary `-`s other than the (A+1)-th character, so it does not\nfollow the format.\n\n* * *"}, {"input": "1 2\n    7444", "output": "No"}]