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 <ctype.h>

int main()
{
    int a,b;
    std::string s;

    std::cin >> a;
    std::cin >> b;
    std::cin >> s;

    if(s[a] == '-' && s.length() == a + b + 1)
    {
        s.erase(a,1);

        for(const auto n : s)
        {
            if(!isdigit(n))
            {
                std::cout<<"No"<<std::endl;
                return 0;
            }
        }

        std::cout<<"Yes"<<std::endl;
    }
    else std::cout<<"No"<<std::endl;
}