#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  int ct = 0, c, e;
  cin >> n >> h;
  vector<int> b;
  int d = 0;
  int max = 0;
  for (int i = 0; i < n; i++) {
    cin >> c >> e;
    b.push_back(e);
    if (c > max) max = c;
  }
  sort(b.begin(), b.end(), greater<int>());
  int i = 0;
  while (b[i] > max) {
    h -= b[i];
    ct++;
    if (h <= 0) break;
    i++;
  }
  if (h > 0) {
    ct += h / max;
    if (h % max != 0) ct++;
  }
  cout << ct << endl;
  return 0;
}
