#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < (n); i++) cin >> a[i] >> b[i];
  sort(a.begin(), a.end(), greater<int>());
  sort(b.begin(), b.end(), greater<int>());
  int res = 0;
  int max_a = a[0];
  int i = 0;
  while (h >= 0 && b[i] > max_a) {
    h -= b[i];
    i++;
    res++;
  }
  if (h > 0) res += (h + max_a - 1) / max_a;
  cout << res << endl;
  return 0;
}
