#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  vector<pair<long long, long long> > mp(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    mp[i] = pair<long long, long long>(a[i], b[i]);
  }
  sort(mp.begin(), mp.end());
  long long num = mp[n - 1].first;
  long long tmp = 0, ans = 0;
  for (int i = 0; i < n; i++) {
    if (mp[i].second > num) {
      tmp += mp[i].second;
      ans++;
    }
    if (tmp >= h) {
      cout << ans << endl;
      return 0;
    }
  }
  long long res = (h - tmp) / num;
  if ((h - tmp) % num)
    cout << res + 1 + ans << endl;
  else
    cout << res + ans << endl;
  return 0;
}
