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.Linq;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        // スペース区切りの整数の入力
        string[] input = Console.ReadLine().Split(' ');
        int a = int.Parse(input[0]);
        int b = int.Parse(input[1]);
        Boolean f = true;
        string c = Console.ReadLine();

        for(int i = 0; i < a; i++)
        {
            char st = c[i];
            try
            {
                int.Parse(st.ToString());
            }
            catch
            {
                f = false;
            }
        }
        if(c[a] != '-')
        {
            f = false;
        }
        for(int i = a + 1; i <= a + b; i++)
        {
            char st = c[i];
            try
            {
                int.Parse(st.ToString());
            }
            catch
            {
                f = false;
            }
        }
        if (f)
        {
            Console.WriteLine("Yes");
        }
        else
        {
            Console.WriteLine("No");
        }
        Console.ReadLine();
    }
}