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 Java7 (OpenJDK 1.7.0) (judge verdict: Wrong Answer)

import java.util.*;
 
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
	int A = sc.nextInt();
	    int B = sc.nextInt();

	    String str = sc.next();
	    char[] c = str.toCharArray();
	    for(int i=0; i<B; i++){
	    	if(i<A){
	    		if(Character.isDigit(c[0])==false){
	    			System.out.println("No");
	    			return;
	    		}
	    	}else if(i==A){
	    		if(!(String.valueOf(c[i]).equals("-"))){
	    			System.out.println("No");
	    			return;
	    		}
	    	}else if(i<=A+B){
	    		if(Character.isDigit(c[0])==false){
	    			System.out.println("No");
	    			return;
	    		}
	    	}
	    }
  }
}