#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

int main() {
  int N, M; cin >> N >> M;
  map<long long, long long> mp;
  for(int i = 0; i < N; i++){
    long long T; cin >> T;
    long long P; cin >> P;
    mp[T] = P;
  }
  long long time = 0, pos = 0;
  for(auto p: mp){
    long long move = abs(p.second - pos);
    long long time2 = p.first - time;
    if(time2 < move){
      cout << "No" << endl;
      return 0;
    }
    time = p.first, pos = p.second;
  }
  cout << "Yes" << endl;
}