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;
typedef long double ld;
typedef pair<int,int> P;
constexpr double EPS = 1e-12;
constexpr int INF = numeric_limits<int>::max()/2;
constexpr int MOD = 1e9+7;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int a,b;cin>>a>>b;
    string s;cin>>s;
    bool f=true;
    for(int i=0;i<(int)s.length();i++){
        if(i==a){
            if(s[i]!='-') f=false;
        }
        else{
            if(s[i]<'0' || '9'<s[i]) f=false;
        }
    }
    if(f) cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
}