#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h;
  cin >> n >> h;
  vector<long long> a(n);
  vector<long long> b(n);
  long long max_a = 0;
  long long idx = 0;
  for (int i = 0; i < (n); i++) {
    cin >> a[i] >> b[i];
    if (max_a < a[i]) {
      max_a = a[i];
      idx = i;
    }
  }
  sort(b.begin(), b.end(), less<long long>());
  long long ans = 0;
  for (int i = 0; i < (n); i++) {
    if (b[i] > 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;
}
