#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> attack(n);
  vector<int> throwing(n);
  for (int i = 0; i < n; ++i) cin >> attack[i] >> throwing[i];
  int maxAttack = 0;
  int sumThrowing = 0;
  int throwingCount = 0;
  for (int i = 0; i < n; ++i) maxAttack = max(maxAttack, attack[i]);
  for (int i = 0; i < n; ++i) {
    if (maxAttack < throwing[i]) {
      sumThrowing += throwing[i];
      throwingCount++;
      if (sumThrowing >= h) break;
    }
  }
  h -= sumThrowing;
  if (h < 0) h = 0;
  int ansCount = (h / maxAttack) + throwingCount;
  if (h % maxAttack) ansCount++;
  cout << ansCount << endl;
  return 0;
}
