#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, h, ans = 0;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  for (int i = 0; i < (n); i++) cin >> a.at(i) >> b.at(i);
  sort(b.rbegin(), b.rend());
  sort(a.rbegin(), a.rend());
  for (int i = 0; i < (b.size() - 1); i++) {
    if (b.at(i) < a.at(0)) b.erase(b.begin() + i);
  }
  for (int i = 0; i < (b.size() - 1); i++) {
    h -= b.at(i);
    ans++;
    if (h <= 0) break;
  }
  if (h > 0) ans += (h + (a.at(0) - 1)) / a.at(0);
  cout << ans;
}
