#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h, x, amax = 0;
  cin >> n >> h;
  int b[n];
  for (int i = 0; i < n; i++) {
    cin >> x >> b[i];
    amax = max(amax, x);
  }
  sort(b, b + n, [](const int &a, const int &b) -> bool { return a > b; });
  int i = 0;
  while (h > 0 && amax <= b[i] && i < n) h -= b[i++];
  cout << i + ceil(h / amax);
  return 0;
}
