#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll INF = (ll)1e18 + 1;
const ll DIV = 1000000007;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll N, H;
  cin >> N >> H;
  vector<ll> a(N);
  vector<ll> b(N);
  ll max_a = 0;
  ll max_a_index = 0;
  ll max_a2 = 0;
  ll max_a2_index = 0;
  for (size_t i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    if (a[i] > max_a) {
      max_a2 = max_a;
      max_a2_index = max_a_index;
      max_a = a[i];
      max_a_index = i;
    }
  }
  ll count = 0;
  for (ll i = 0; i < N; i++) {
    if (b[i] > max_a) {
      H -= b[i];
      count++;
    }
  }
  ll a_count;
  a_count = H / max_a;
  if (H % max_a > 0) a_count++;
  cout << a_count + count << endl;
  return 0;
}
