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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

// ARC 86-D
// https://beta.atcoder.jp/contests/arc086/tasks/arc086_b

public class Main {

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		
		int A = in.nextInt();
		int B = in.nextInt();
		String s = in.next();
		
		boolean isValid = true;
		if (s.length() != A + B + 1) {
			isValid = false;
		}
		if (s.charAt(A) != '-') {
			isValid = false;
		}
		for (int i = 0; i < s.length(); i++) {
			if (i != A && !('0' <= s.charAt(i) && s.charAt(i) <= '9')) {
				isValid = false;
			}
		}
		System.out.println(isValid ? "Yes" : "No");
	}
}