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