#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<pair<int, int>> v;
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    v.push_back(make_pair(b, a));
  }
  sort(v.begin(), v.end());
  int count = 0;
  for (int i = v.size() - 1; i >= 0; i--) {
    h -= v[i].first;
    count++;
    if (h <= 0) {
      break;
    }
  }
  if (h <= 0) {
    cout << fixed << count << "\n";
  } else {
    cout << fixed << count + ceil(h / v[0].second) << "\n";
  }
  return 0;
}
