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