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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.*;

public class Main {
  public static void main(String[] args) throws Exception {
    
    Scanner sc = new Scanner(System.in);
    int A = sc.nextInt();
    int B = sc.nextInt();
    String S = sc.next();
    if (S.length() != A + B + 1){
      System.out.println("No");
    }
    String case1 = S.substring(0, A);
    char case2 = S.charAt(A);
    String case3 = S.substring(A+1);
 
    if (!case1.matches("[0-9]*")) {
      System.out.println("No");
      return;
    }
    if (case2 != '-') {
      System.out.println("No");
      return;
    }
    if (case3.matches("[0-9]*")) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
}