#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
void solve(int cc) {
  long long s, n;
  cin >> s >> n;
  vector<pair<long long, long long>> d(n);
  for (int i = 0; i < n; i++) {
    cin >> d[i].first >> d[i].second;
  }
  sort(
      d.begin(), d.end(),
      [&](const pair<long long, long long> aa,
          const pair<long long, long long> bb) { return aa.first < bb.first; });
  sort(d.begin(), d.end(),
       [&](const pair<long long, long long> aa,
           const pair<long long, long long> bb) {
         if (aa.first == bb.first) return aa.second > bb.second;
         return aa.first < bb.first;
       });
  for (auto p : d) {
    s -= p.first;
    if (s <= 0) {
      cout << "NO" << '\n';
      return;
    }
    s += p.second;
    s += p.first;
  }
  cout << "YES" << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve(1);
  return 0;
}
