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<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF= 1LL << 60;
#define REP(i,n) for(ll i=0; i<n; i++)
#define FOR(i,a,n) for(ll i=a; i<n; i++)
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int a,b;
    string s;
    cin >> a >> b;
    cin >> s;
    int f= 1;
    REP(i,s.length()){
        if(i==a){
            if(s[i]!='-'){
                f= 0;
                break;
            }
        }else{
            if(0<=s[i]-'0' && s[i]-'0' <=9){

            }else{
                f=0;
                break;
            }        
        }
    }
    cout << ((f)?"Yes":"No") << endl;
}