#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  int max_a = 0;
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
    max_a = max(max_a, a[i]);
  }
  sort(b.begin(), b.end(), greater<int>());
  int ans = 0;
  for (int i = 0;; ++i) {
    if (b[i] <= max_a || i == n) {
      ans += h / max_a + bool(h % max_a);
      break;
    } else {
      h -= b[i];
      ++ans;
      if (h < 0) break;
    }
  }
  cout << ans << endl;
}
