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;
 
int gcd(int x,int y){
    if(y==0)return x;

    return gcd(y,x%y);
}
int lcm(int x,int y){
    return x*y/gcd(x,y);
}

int ctoi(char c) {
	if (c >= '0' && c <= '9') {
		return c - '0';
	}
	return 0;
}

int main(){

    int A,B;
    string S;
    cin>>A>>B>>S;

    for(int i=0;i<A;i++){
        if(S[i]<'0'||'9'<S[i]){
            cout<<"No"<<endl;
            return 0;
        }
    }

    if(S[A]!='-'){
        cout<<"No"<<endl;
        return 0;
    }

    for(int i=A+1;i<S.length();i++){
        if(S[i]<'0'||'9'<S[i]){
            cout<<"No"<<endl;
            return 0;
        }
    }

    cout<<"Yes"<<endl;

    return 0;
}