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;
using System.Collections.Generic;
using System.Text;


public class B
{
	public static void Main()	
	{
		string[] args = Console.ReadLine().Split(' ');
		int A = Int32.Parse(args[0]);
		int B = Int32.Parse(args[1]);
		string S = Console.ReadLine();

		bool isCorrect = (S[A] == '-');
		for(int i = 0; i < A + B + 1; i++)
		{
			if(i == A)
				continue;
			else if((S[i] < '0') || (S[i] > '9'))
			{
				isCorrect = false;
				break;
			}
		}

		Console.WriteLine(isCorrect ? "Yes" : "No");
	}
}