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

fn main() {
    let mut buffer = String::new();
    stdin().read_line(&mut buffer).ok();
    let mut itr = buffer.split_whitespace().map(|x| i64::from_str(x).unwrap());
    let (_n, m) = (itr.next().unwrap(), itr.next().unwrap());

    let mut v = Vec::new();
    for _i in 0..m {
        buffer.clear();
        stdin().read_line(&mut buffer).ok();
        let mut itr = buffer.split_whitespace().map(|x| i64::from_str(x).unwrap());
        let (t, p) = (itr.next().unwrap(), itr.next().unwrap());
        v.push((t, p));
    }

    let mut ret = true;

    let mut t = 0;
    let mut pos = 0;
    for i in 0..v.len() {
        let dist = pos - v[i].0;
        let diff_time = t - v[i].1;

        if dist > diff_time {
            ret = false;
        }
        t = v[i].0;
        pos = v[i].1;
    }

    match ret {
        true => println!("Yes"),
        false => println!("No"),
    }
}