#include <bits/stdc++.h>
using namespace std;
constexpr int64_t mod = 1e9 + 7;
int main() {
  int n;
  int h;
  cin >> n >> h;
  vector<pair<int, int>> sword(n);
  for (int i = 0; i < n; ++i) {
    int a, b;
    cin >> a >> b;
    sword[i] = make_pair(a, -b);
  }
  sort(sword.begin(), sword.end(), greater<pair<int, int>>());
  int tmp = sword[0].first;
  int cnt = 0;
  for (auto&& e : sword) {
    e.second *= -1;
  }
  for (int i = 0; i < n; ++i) {
    if (sword[i].second > tmp) {
      h -= sword[i].second;
      cnt++;
    }
    if (h <= 0) {
      cout << cnt;
      return 0;
    }
  }
  cnt += h / tmp + ((h % tmp > 0) ? 1 : 0);
  cout << cnt;
}
