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: Accepted)

import java.util.Scanner;

public class Main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt(), b = sc.nextInt();
		String s = sc.next();
		String ans[] = {"Yes", "No"};
		sc.close();
		int an = 0;
		int n = s.length();
		for(int i = 0; i < a; ++i) {
			if(s.charAt(i) < '0' || s.charAt(i) > '9') {
				an = 1;
				break;
			}
		}
		if(s.charAt(a) != '-')an = 1;
		if(an != 1) {
			for(int i = a + 1; i < n; ++i) {
				if(s.charAt(i) < '0' || s.charAt(i) > '9') {
					an = 1;
					break;
				}
			}
		}
		System.out.println(ans[an]);
	}
}