#include <bits/stdc++.h>
int main() {
  long long n, h;
  std::cin >> n >> h;
  std::vector<std::pair<long long, long long>> a(n);
  std::pair<long long, long long> kiru;
  for (long long i = 0; i < n; i++) std::cin >> a[i].first >> a[i].second;
  std::sort(a.begin(), a.end());
  kiru = a.back();
  a.pop_back();
  n--;
  long long cnt = 0;
  for (long long i = 0; i < n; i++) std::swap(a[i].first, a[i].second);
  std::sort(a.begin(), a.end(),
            std::greater<std::pair<long long, long long>>());
  for (long long i = 0; a[i].first > kiru.first && h > 0 && i < n; i++) {
    h -= a[i].first;
    cnt++;
  }
  std::cerr << kiru.first << " : " << kiru.second << std::endl;
  h -= kiru.second;
  cnt++;
  if (h > 0) cnt += std::max(0LL, (h + kiru.first - 1) / kiru.first);
  std::cout << cnt << std::endl;
}
