#![allow(unused_imports)]
#![allow(non_snake_case)]
use std::cmp::*;
use std::collections::*;
use std::io::Write;

#[allow(unused_macros)]
macro_rules! debug {
    ($($e:expr),*) => {
        #[cfg(debug_assertions)]
        $({
            let (e, mut err) = (stringify!($e), std::io::stderr());
            writeln!(err, "{} = {:?}", e, $e).unwrap()
        })*
    };
}

fn main() {
    let v = read_vec::<usize>();
    let (n, m) = (v[0], v[1]);

    let mut drags = vec![];
    for i in 0..m {
        let v = read_vec::<i64>();
        let (t, p) = (v[0], v[1]);

        drags.push((t, p));
    }

    let mut cur = 0;
    let mut cur_t = 0;
    for (t, p) in drags {
        if (p - cur).abs() > (t - cur_t) {
            println!("No");
            return;
        }
        cur = p;
        cur_t = t;
    }
    println!("Yes");
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}