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