//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int main(){
  int N, M; cin >> N >> M;
  ll now = 0, nowp = 0;
  
  for(int i = 0; i < M; i++){
    ll T, P; cin >> T >> P;
    ll lestT = T-now, lestP = abs(P-nowp);
    
    if(lestT < lestP){
      printl("No");
      return 0;
    }
    
    now = T;
    nowp = P;
  }
  
  printl("Yes");
  
  return 0;
}