#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  priority_queue<pair<int, int>> data;
  for (int i = (0); i < (n); ++i) {
    int x, y;
    cin >> x >> y;
    pair<int, int> p = make_pair(x, y);
    data.push(p);
  }
  pair<int, int> p = data.top();
  int a_max = p.first;
  int b_val = p.second;
  data.pop();
  priority_queue<pair<int, int>> data2;
  while (!data.empty()) {
    pair<int, int> p = data.top();
    data.pop();
    data2.push(make_pair(p.second, p.first));
  }
  int ans = 0;
  while (h > 0 && !data2.empty()) {
    pair<int, int> p = data2.top();
    data2.pop();
    if (p.first > a_max) {
      h -= p.first;
      ans++;
    } else {
      break;
    }
  }
  if (h > 0) {
    h -= b_val;
    ans++;
  }
  if (h > 0) {
    ans += (h / a_max);
    if (h % a_max != 0) {
      ans += 1;
    }
  }
  cout << ans << endl;
}
