#include <bits/stdc++.h>
using namespace std;
template <typename T>
std::ostream &operator<<(std::ostream &out, vector<T> &v) {
  for (typename vector<T>::size_type i = 0; i < v.size(); ++i)
    out << v[i] << " ";
  out << "\n";
  return out;
}
template <typename T, typename N>
std::ostream &operator<<(std::ostream &out, vector<pair<T, N> > &v) {
  for (size_t i = 0; i < v.size(); ++i)
    out << "(" << v[i].first << ", " << v[i].second << ") ";
  out << "\n";
  return out;
}
template <typename T>
std::ostream &operator<<(std::ostream &out, vector<vector<T> > &v) {
  for (size_t i = 0; i < v.size(); ++i) {
    for (size_t j = 0; j < v[i].size(); ++j) {
      out << v[i][j] << " ";
    }
    out << "\n";
  }
  return out;
}
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n, h;
  cin >> n >> h;
  vector<pair<int, int> > katanas(n);
  int a, b;
  int max_damage = -1;
  for (int i = 0; i < n; ++i) {
    cin >> a >> b;
    katanas[i] = {b, a};
    max_damage = max(max_damage, a);
  }
  sort(katanas.rbegin(), katanas.rend());
  int attacks = 0;
  int i = 0;
  while (katanas[i].second != max_damage) {
    h -= katanas[i].first;
    ++attacks;
    if (h <= 0) {
      cout << attacks << "\n";
      return 0;
    }
    ++i;
  }
  int j = i + 1;
  while (j < n && katanas[j].first > max_damage) {
    h -= katanas[j].first;
    ++attacks;
    if (h < 0) {
      cout << attacks << "\n";
      return 0;
    }
    ++j;
  }
  attacks += ceil(max(0, h - katanas[i].first) / (double)katanas[i].second);
  cout << attacks + 1 << "\n";
  return 0;
}
