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;

namespace AtCoder1230_2
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] input = Console.ReadLine().Split(' ');
            int a = int.Parse(input[0]);
            int b = int.Parse(input[1]);

            var c = Console.ReadLine();
            bool isYubin = true;

            for (int i = 0; i < a; i++)
            {
                if (c[i] < '0' || '9' < c[i])
                {
                    isYubin = false;
                }
            }
            if(c[a] != '-'){
                isYubin = false;
            }

            for (int i = a + 1; i < c.Length; i++)
            {
                if (c[i] < '0' || '9' < c[i])
                {
                    isYubin = false;
                }
            }

            if(c.Length != a+b+1){
                isYubin = false;
            }

            if(isYubin == true){
                Console.WriteLine("Yes");
            }else{
                Console.WriteLine("No");
            }
        }
    }
}