#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll N, H;
  cin >> N >> H;
  vector<ll> a(N), b(N);
  for (ll i = 0; i < N; ++i) {
    cin >> a[i] >> b[i];
  }
  ll max_a = *max_element(a.begin(), a.end());
  sort(b.begin(), b.end(), greater<ll>());
  ll ans = 0;
  for (ll i = 0; i < N; ++i) {
    if (b[ans] > max_a) {
      H -= b[i];
      ++ans;
      if (H < 0) {
        cout << ans << endl;
        return 0;
      }
    }
  }
  if (H % max_a == 0) {
    cout << ans + H / max_a << endl;
  } else {
    cout << ans + H / max_a + 1 << endl;
  }
  return 0;
}
