#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  int amax = 0;
  for (int i = 0; i < (n); i++) {
    cin >> a[i] >> b[i];
    amax = max(amax, a[i]);
  }
  sort(b.rbegin(), b.rend());
  int i = 0;
  int ans = 0;
  while (b[i] >= amax && i < n) {
    h -= b[i];
    i++;
    ans++;
  }
  if (h <= 0) {
    cout << ans << endl;
    return 0;
  }
  if (h % amax)
    ans += (h / amax) + 1;
  else
    ans += (h / amax);
  cout << ans << endl;
  return 0;
}
