#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll atcoder_mod = 1e9 + 7;
template <typename T = int>
T in() {
  T x;
  cin >> x;
  return (x);
}
template <typename T = int, typename C = vector<T>>
C vecin(int N) {
  C x(N);
  for (int i = 0; i < (N); ++i) {
    x[i] = in<T>();
  }
  return move(x);
}
void vout() { cout << endl; }
template <typename Head, typename... Tail>
void vout(Head&& h, Tail&&... t) {
  cout << ' ' << h;
  vout(forward<Tail>(t)...);
}
void out() { cout << endl; }
template <typename Head, typename... Tail>
void out(Head&& h, Tail&&... t) {
  cout << h;
  vout(forward<Tail>(t)...);
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int N = in(), H = in();
  vector<pair<int, int>> P(N);
  int MA = 0;
  for (int i = 0; i < (N); ++i) {
    P[i].first = in();
    P[i].second = in();
    MA = max(MA, P[i].first);
  }
  sort(P.begin(), P.end(),
       [](const pair<ll, ll>& lhs, const pair<ll, ll>& rhs) {
         return lhs.second > rhs.second;
       });
  int num = 0;
  for (int i = 0; i < (N); ++i) {
    if (P[i].second >= MA) {
      H -= P[i].second;
      num++;
    }
    if (P[i].second < MA) break;
  }
  num += (H + MA - 1) / MA;
  out(num);
  return 0;
}
