#include <bits/stdc++.h>
using namespace std;
template <typename T0, typename T1>
std::ostream& operator<<(std::ostream& os, const map<T0, T1>& v) {
  for (typename map<T0, T1>::const_iterator p = v.begin(); p != v.end(); p++) {
    os << p->first << ": " << p->second << " ";
  }
  return os;
}
template <typename T0, typename T1>
std::ostream& operator<<(std::ostream& os, const pair<T0, T1>& v) {
  os << v.first << ": " << v.second << " ";
  return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os, const vector<T>& v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << " ";
  }
  return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os, const set<T>& v) {
  vector<T> tmp(v.begin(), v.end());
  os << tmp;
  return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os, const deque<T>& v) {
  vector<T> tmp(v.begin(), v.end());
  os << tmp;
  return os;
}
template <typename T>
std::ostream& operator<<(std::ostream& os, const vector<vector<T>>& v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << endl;
  }
  return os;
}
template <typename T>
void maxUpdate(T& a, T b) {
  a = max(a, b);
}
template <typename T>
void minUpdate(T& a, T b) {
  a = min(a, b);
}
string YN(bool v) { return v ? "Yes" : "No"; }
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long N, H;
  while (cin >> N >> H) {
    vector<pair<long long, long long>> AB(N);
    for (long long i = 0, _n = (N); (i) < (long long)_n; ++i)
      cin >> AB[i].first >> AB[i].second;
    sort((AB).rbegin(), (AB).rend());
    vector<long long> bs;
    for (long long i = (long long)1, _b = (long long)(N); (i) < _b; ++i)
      if (AB[0].first <= AB[i].second) bs.push_back(AB[i].second);
    sort((bs).rbegin(), (bs).rend());
    long long ans = 0;
    for (long long i = 0, _n = (bs.size()); (i) < (long long)_n; ++i) {
      H -= bs[i];
      ans++;
      if (H <= 0) break;
    }
    if (0 < H && AB[0].first < AB[0].second) {
      ans++;
      H -= AB[0].second;
    }
    if (0 < H) {
      ans += (H + AB[0].first - 1) / AB[0].first;
    }
    cout << ans << endl;
  }
  return 0;
}
