#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H;
  vector<int> a;
  vector<int> b;
  cin >> N >> H;
  int amax = 0;
  int ia, ib;
  for (int i = 0; i < N; i++) {
    cin >> ia >> ib;
    a.push_back(ia);
    b.push_back(ib);
    amax = max(amax, ia);
  }
  sort(b.begin(), b.end());
  int count = 0;
  for (int i = 0; i < N; i++) {
  }
  for (int i = N - 1; i < N && b[i] > amax; i--) {
    H -= b[i];
    count += 1;
    if (H <= 0) {
      cout << count << endl;
      return 0;
    }
  }
  int ans = H / amax + count;
  cout << ans << endl;
  return 0;
}
