#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  cin >> N >> H;
  vector<pair<int, int>> da(N);
  for (int i = 0; i < N; i++) cin >> da[i].second >> da[i].first;
  sort(da.begin(), da.end());
  for (int i = N - 1; i >= 0; i--) {
    H -= da[i].first;
    if (H <= 0) {
      cout << i + 1 << endl;
      return 0;
    }
  }
  int ma = 0;
  for (int i = 0; i < N; i++) {
    if (ma < da[i].second) ma = da[i].second;
  }
  int ans = H / ma;
  if (H % ma) ans++;
  cout << N + ans << endl;
}
