#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n);
  vector<int> b(n);
  int amax = 0;
  int amaxi = 0;
  for (int i = 0; i < (n); ++i) {
    cin >> a.at(i) >> b.at(i);
    if (a.at(i) > amax) {
      amax = a.at(i);
      amaxi = i;
    }
  }
  int cou = 0;
  for (int i = 0; i < (n); ++i) {
    if (b.at(i) > a.at(amaxi) && i != amaxi) {
      h -= b.at(i);
      cou++;
      if (h <= 0) {
        cout << cou << endl;
        return 0;
      }
    }
  }
  if (a.at(amaxi) < b.at(amaxi)) {
    h -= b.at(amaxi);
    cou++;
    if (h <= 0) {
      cout << cou << endl;
      return 0;
    }
  }
  if (h % a.at(amaxi) == 0) {
    cou += h / a.at(amaxi);
  } else {
    cou += h / a.at(amaxi);
    cou++;
  }
  cout << cou << endl;
  return 0;
}
