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 Rust (1.15.1) (judge verdict: Accepted)

use std::io::*;
use std::str::FromStr;

fn main() {
    let stdin = stdin();
    let mut lock = stdin.lock();
    let mut str1 = String::new();
    lock.read_to_string(&mut str1).unwrap();
    let mut iter1 = str1.trim().split_whitespace();
    let a = usize::from_str(iter1.next().unwrap()).unwrap();
    let _b = usize::from_str(iter1.next().unwrap()).unwrap();
    //let chars: Vec<_> = iter1.next().unwrap().chars().collect();
    let chars = iter1.next().unwrap().chars();
    for (i, item) in chars.enumerate() {
        if a == i {
            if item != '-' {
                println!("No");
                return;
            } else {
                continue;
            }
        }
        if item.is_digit(10) == false {
            println!("No");
            return;
        }
    }
    println!("Yes");
}