#include <bits/stdc++.h>
using namespace std;
int main() {
  int64_t n, h;
  cin >> n >> h;
  int64_t a[n], b[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(b, b + n);
  reverse(b, b + n);
  int64_t a_max_v = *max_element(a, a + n);
  int64_t ans = h;
  for (int64_t i = 0; i <= n; i++) {
    if (0 < i) {
      h -= b[i - 1];
    }
    ans = min(ans, i + (h + a_max_v - 1) / a_max_v);
    if (h <= 0) {
      break;
    }
  }
  cout << ans << endl;
  return 0;
}
