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: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

namespace ABC084_B_Postal_Code
{
	internal class Program
	{
		public static void Main(string[] args)
		{
			string[] input = Console.ReadLine().Split(' ');
			int a = int.Parse(input[0]);
			int b = int.Parse(input[1]);
			string s = Console.ReadLine();
			List<string> sList = new List<string>();

			for (int i = 0; i < s.Length; i++)
				sList.Add(s.Substring(i, 1));
			
			int hihunCount = sList.Count(x => x == "-");
			if (hihunCount != 1 || sList.Count != a + b + 1)
			{
				Console.WriteLine("No");
			}
			else if (sList[a] == "-")
			{
				Console.WriteLine("Yes");
			}
			else
			{
				Console.WriteLine("No");
			}
		}
	}
}