#include <bits/stdc++.h>
using namespace std;
int main() {
  long long N, H, a_max = 0, atk = 0;
  cin >> N >> H;
  vector<pair<long long, long long>> sword(N);
  for (long long i = (0); i < (N); i++) {
    long long a, b;
    cin >> a >> b;
    sword[i] = make_pair(b, a);
    if (a_max < a) a_max = a;
  }
  sort(sword.begin(), sword.end());
  for (long long i = (0); i < (N); i++) {
    if (sword[i].first > a_max) {
      H -= sword[i].first;
      atk++;
      if (H <= 0) {
        cout << atk << endl;
        return 0;
      }
    }
  }
  atk += H / a_max;
  if (H % a_max) atk++;
  cout << atk << endl;
}
