#![allow(unused_imports)]
#![allow(dead_code)]

use std::thread;
use std::io::{ self, Read };
use std::fmt;
use std::iter::Iterator;
use std::cmp::*;
use std::collections::*;
use std::str::*;

#[derive(Default)]
struct Input {
    buf: Vec<String>
}

impl Input {
    fn new() -> Input {
        Input { buf: Vec::new() }
    }

    fn read<T: FromStr>(&mut self) -> T 
    where <T as FromStr>::Err: fmt::Debug {
        self.next().unwrap().parse::<T>().unwrap()
    }

    fn read_2<T: FromStr, U: FromStr>(&mut self) -> (T, U)
    where <T as FromStr>::Err: fmt::Debug,
          <U as FromStr>::Err: fmt::Debug {
        (self.read(), self.read())
    }

    fn read_bytes(&mut self) -> Vec<u8> {
        self.next().unwrap().into_bytes()
    }

    fn read_n<T: FromStr>(&mut self, n: usize) -> Vec<T>
    where <T as FromStr>::Err: fmt::Debug {
        let mut v = Vec::new();
        for _ in 0..n { v.push(self.read::<T>()); }
        v
    }
}

impl Iterator for Input {
    type Item = String;
    fn next(&mut self) -> Option<String> {
        while self.buf.is_empty() {
            let mut s = String::new();
            let _res = io::stdin().read_line(&mut s);
            self.buf = s.split_whitespace().map(|s| s.to_owned()).collect::<Vec<_>>();
            self.buf.reverse();
        }
        self.buf.pop()
    }
}

fn f(a: usize, s: &[u8]) -> bool {
    for (i, c) in s.iter().enumerate() {
        if i == a {
            if *c != b'-' { return false; }
        } else {
            if !c.is_ascii_digit() { return false; }
        }
    }
    true
}

fn run() {
    let mut ip = Input::new();
    let a: usize = ip.read();
    let _b: usize = ip.read();
    let s = ip.read_bytes();
    if f(a, &s) {
        println!("Yes");
    } else {
        println!("No");
    }
}

fn main() {
    let _ = thread::Builder::new()
        .stack_size(10 * 1024 * 1024)
        .spawn(run).unwrap()
        .join();
}