pub fn readln() -> String {
    let mut line = String::new();
    ::std::io::stdin()
        .read_line(&mut line)
        .unwrap_or_else(|e| panic!("{}", e));
    line
}
macro_rules !read {($($t :tt ) ,*;$n :expr ) =>{{let stdin =::std ::io ::stdin () ;let ret =::std ::io ::BufRead ::lines (stdin .lock () ) .take ($n ) .map (|line |{let line =line .unwrap () ;let mut it =line .split_whitespace () ;_read !(it ;$($t ) ,*) } ) .collect ::<Vec <_ >>() ;ret } } ;($($t :tt ) ,*) =>{{let line =readln () ;let mut it =line .split_whitespace () ;_read !(it ;$($t ) ,*) } } ;}
macro_rules !_read {($it :ident ;[char ] ) =>{_read !($it ;String ) .chars () .collect ::<Vec <_ >>() } ;($it :ident ;[u8 ] ) =>{Vec ::from (_read !($it ;String ) .into_bytes () ) } ;($it :ident ;usize1 ) =>{$it .next () .unwrap_or_else (||panic !("input mismatch" ) ) .parse ::<usize >() .unwrap_or_else (|e |panic !("{}" ,e ) ) -1 } ;($it :ident ;[usize1 ] ) =>{$it .map (|s |s .parse ::<usize >() .unwrap_or_else (|e |panic !("{}" ,e ) ) -1 ) .collect ::<Vec <_ >>() } ;($it :ident ;[$t :ty ] ) =>{$it .map (|s |s .parse ::<$t >() .unwrap_or_else (|e |panic !("{}" ,e ) ) ) .collect ::<Vec <_ >>() } ;($it :ident ;$t :ty ) =>{$it .next () .unwrap_or_else (||panic !("input mismatch" ) ) .parse ::<$t >() .unwrap_or_else (|e |panic !("{}" ,e ) ) } ;($it :ident ;$($t :tt ) ,+) =>{($(_read !($it ;$t ) ) ,*) } ;}

fn main() {
    let (_, m) = read!(usize, usize);
    let mut t = Vec::with_capacity(m);
    let mut p = Vec::with_capacity(m);
    for (_t, _p) in (0..m).map(|_| read!(i64, i64)) {
        t.push(_t);
        p.push(_p);
    }
    let mut tn = 0;
    let mut pn = 0;
    for (&t, &p) in t.iter().zip(p.iter()) {
        if (t - tn).abs() < (p - pn).abs() {
            println!("No");
            return;
        }
        tn = t;
        pn = p;
    }
    println!("Yes");
}