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 (1.42.0) (judge verdict: Accepted)

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

fn input_tuple() -> (u64, u64) {
    let mut line: String = String::new();
    io::stdin().read_line(&mut line);
    let vec: Vec<u64> = line.split_whitespace().map(|s| s.parse().unwrap()).collect();
    (vec[0], vec[1])
}

fn input_char_vec() -> Vec<char> {
    let mut line: String = String::new();
    io::stdin().read_line(&mut line);
    line.trim().chars().collect()
}

fn main() {
    let (a, b) = input_tuple();  
    let s = input_char_vec();
    for i in 0..(a+b+1) {
        if i == a {
            if s[i as usize] != '-' {
                println!("No");
                return;
            }
        } else {
            if (s[i as usize] as u64) < ('0' as u64) || s[i as usize] as u64 > '9' as u64 {
                println!("No");
                return;
            }
        }
    }
    println!("Yes");
}