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 <iostream>
#include <string>
#include <cmath>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

int a, b;
string s;

int main(){
    cin >> a >> b;
    cin >> s;
    int ac = 0, bc = 0, ch = 0;
    for(int i = 0; i < s.length(); i++){   
        if(i != a){
            if(s[i] == '-'){
                cout << "No\n";
                return 0;
            }
            if(ch == 0){
                ++ac;
            }
            else{
                ++bc;
            }
        }
        else{
            if(s[i] != '-'){
                cout << "No\n";
                return 0;
            }
            ch = 1;
        }
    }

    if(ac != a || bc != b){
        cout << "No\n";
        return 0;
    }
    cout << "Yes\n";
}