#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> a(N, 0);
  vector<int> b(N, 0);
  for (int i = 0; i < N; i++) cin >> a[i] >> b[i];
  if (H <= 0) {
    cout << 0 << "\n";
    return 0;
  }
  int max_a = 0;
  for (int i = 0; i < N; i++) {
    max_a = max(max_a, a[i]);
  }
  int count = 0;
  for (int i = 0; i < N; i++) {
    if (b[i] > max_a) {
      count++;
      H -= b[i];
      if (H <= 0) {
        cout << count << "\n";
        return 0;
      }
    }
  }
  int ans = count + H / max_a;
  if (H % max_a != 0) ans++;
  cout << ans << "\n";
  return 0;
}
