#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  ll n, h;
  cin >> n >> h;
  vector<ll> a(n), b(n);
  for (int i = 0; i < n; i++) cin >> a.at(i) >> b.at(i);
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  reverse(a.begin(), a.end());
  reverse(b.begin(), b.end());
  for (int i = 0; i < n; i++) {
    h -= b.at(i);
    if (h <= 0) {
      cout << i + 1 << endl;
      return 0;
    }
  }
  if (h % a.at(0) == 0)
    cout << n + h / a.at(0) << endl;
  else
    cout << n + 1 + h / a.at(0) << endl;
  return 0;
}
