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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

class Problem_B
{
  public static void Main(string[] args)
  {
    var input = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
    int a = input[0], b = input[1];
    var s = Console.ReadLine();
    if (s.IndexOf("-") != a)
    {
      Console.WriteLine("No");
      return;
    }
    foreach (var c in s)
    {
      if (c == '-') continue;
      if (c < '0' || c > '9')
      {
        Console.WriteLine("No");
        return;
      }
    }
    Console.WriteLine("Yes");
  }
}