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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <iomanip>
#include <iostream>
#include <string>
#include <vector>

typedef long long ll;
using namespace std;

int main() {
    int a = 0, b = 0;
    cin >> a >> b;
    string s = "";
    cin >> s;
    if (s.at(a) != '-') cout << "No" << endl;
    else {
        for (int i=0; i<a+b+1; i++) {
            if (i == a) continue;
            else if (s.at(i) < '0' || s.at(i) > '9') {
                cout << "No" << endl;
                return 0;
            }
        }
        cout << "Yes" << endl;
    }
    return 0;
}