#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<int> a(N), b(N);
  vector<pair<int, int>> s(N);
  for (int i = 0; i < N; i++) {
    cin >> a.at(i) >> b.at(i);
    s.at(i) = make_pair(a.at(i), b.at(i));
  }
  sort(s.begin(), s.end());
  int A = s.at(N - 1).first, B = s.at(N - 1).second;
  sort(b.begin(), b.end(), greater<int>());
  int ans = 0;
  for (int i = 0; i < N && b.at(i) > A; i++) {
    H -= b.at(i);
    ans++;
    if (H <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
  while (H > 0) {
    H -= A;
    ans++;
  }
  cout << ++ans << endl;
}
