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 ABC084_B
{
    class Program
    {
        static void Main(string[] args)
        {
            var sss = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
            var a = sss[0];
            var b = sss[1];
            var S = Console.ReadLine();
            var i = 0;
            var j = 0;

            if(!(S[a] == '-'))
            {
                Console.WriteLine("No");
                return;
            }
            var A = S.Substring(0, a);
            bool resultA = int.TryParse(A, out i);
            var B = S.Substring(a + 1, b);
            bool resultB = int.TryParse(B, out j);
            if(!(resultA == true && resultB == true))
            {
                Console.WriteLine("No");
                return;
            }
            Console.WriteLine("Yes");
        }
    }
}