#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  int maxattack = a[n - 1];
  int maxthrow = b[n - 1];
  int ans = 0;
  if (maxattack >= maxthrow) {
    ans = (h + maxattack - 1) / maxattack;
  } else {
    vector<int>::iterator ub = upper_bound(b.begin(), b.end(), maxattack);
    bool flag = false;
    for (; ub != b.end(); ub++) {
      ans++;
      h -= *ub;
      if (h <= 0) {
        flag = true;
        break;
      }
    }
    if (!flag) {
      ans += (h + maxattack - 1) / maxattack;
    }
  }
  cout << ans << endl;
  return 0;
}
