#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int N, M;
  cin >> N >> M;
  int64_t t = 0, p = 0;
  for (int i = 0; i < M; i++) {
    int64_t tt, pp;
    cin >> tt >> pp;
    if (tt - t < abs(pp - p)) {
      cout << "No" << '\n';
      return 0;
    }
  }
  cout << "Yes" << '\n';
  return 0;
}