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.Text.RegularExpressions;
using static System.Console;
using static System.Convert;

class Program
{
    static void Main(string[] args)
    {
        var input = ReadLine().Split(' ');
        var num1 = ToInt32(input[0]);
        var num2 = ToInt32(input[1]);
        var str = ReadLine();
        var rgx = new Regex(string.Format(@"\d{{0}}-\d{{1}}",num1,num2));
        WriteLine(rgx.IsMatch(str) ? "Yes" : "No");
    }
}