#include <bits/stdc++.h>
using namespace std;
template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "(" << p.first << "," << p.second << ")";
  return os;
}
template <class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "{";
  for (int i = 0, i_len = ((int)v.size()); i < i_len; ++i) {
    if (i) os << ",";
    os << v[i];
  }
  os << "}";
  return os;
}
template <typename T, size_t S>
void printArray(const T (&array)[S]) {
  for (auto val : array) std::cout << val << ", ";
  std::cout << "\n";
}
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }
const double PI = acos(-1);
const long long MOD = 1000000007;
using Graph = vector<vector<int>>;
void solve() {
  long long n, h;
  cin >> n >> h;
  vector<pair<long long, long long>> vp;
  for (int i = 0, i_len = (n); i < i_len; ++i) {
    long long a, b;
    cin >> a >> b;
    vp.push_back({a, b});
  }
  sort((vp).rbegin(), (vp).rend());
  long long res = 0;
  for (auto x : vp) {
    if (h > 0) {
      if (x.second > vp[0].first) {
        h -= x.second;
        res++;
      }
    }
  }
  if (h > 0) {
    res += h / vp[0].first;
    if (h % vp[0].first > 0) res++;
  }
  cout << res << endl;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
}
