#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int n, h;
  cin >> n >> h;
  vector<pair<int, int>> kp(n);
  int a_max = 0;
  for (int i = 0; i < n; ++i) {
    cin >> kp[i].second >> kp[i].first;
    a_max = max(a_max, kp[i].second);
  }
  sort((kp).begin(), (kp).end());
  auto it = upper_bound((kp).begin(), (kp).end(), make_pair(a_max, 0));
  int use_index = distance(kp.begin(), it);
  int b_sum = 0;
  for (int i = use_index; i <= n - 1; ++i) b_sum += kp[i].first;
  int ans = 0;
  if (h <= b_sum) {
    for (int i = n - 1; i >= use_index; --i) {
      h -= kp[i].first;
      ans++;
      if (h <= 0) break;
    }
  } else {
    h -= b_sum;
    ans = n - use_index;
    ans += (h + a_max - 1) / a_max;
  }
  cout << ans << endl;
  return 0;
}
