#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const int N = 100005;
vector<int> lst;
int n;
bool compare(int a, int b) { return a > b; }
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  int maxPower = 0, h;
  int cnt = 0;
  cin >> n >> h;
  for (int i = 1; i <= n; ++i) {
    int a, b;
    cin >> a >> b;
    maxPower = max(a, maxPower);
    lst.push_back(b);
  }
  sort(lst.begin(), lst.end(), compare);
  for (auto v : lst) {
    if (v <= maxPower) break;
    h -= v;
    cnt++;
    if (h <= 0) break;
  }
  if (h <= 0) {
    cout << cnt;
    return 0;
  }
  cnt += ceil(h / maxPower);
  cout << cnt;
  return 0;
}
