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 <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cctype>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <vector>
#define ll long long
#define imfor(i, n) for(int i = 0; i < n; i++)
using namespace std;
ll MOD = 1000000007;

int main() {
    int a, b;
    string s;
    cin >> a >> b;
    cin >> s;
    int f = 1;
    imfor(i, s.size()) {
        if (i < a) {
            if (s[i] < '0' || '9' < s[i]) {
                f = 0;
            }
        }
        else if (i == a) {
            if (s[i] != '-') {
                f = 0;
            }
        }
        else {
            if (s[i] < '0' || '9' < s[i]) {
                f = 0;
            }
        }
    }
    if (f == 1) {
        cout << "Yes" << endl;
    }
    else {
        cout << "No" << endl;
    }
}