#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h, a[100000], b[100000], ans = 0;
  cin >> n >> h;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n);
  sort(b, b + n);
  for (int i = n - 1; i >= 0; i++) {
    if (a[n - 1] <= b[i]) {
      h -= b[i];
      ans++;
    }
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    } else {
      ans += (h + a[n - 1] - 1) / a[n - 1];
      break;
    }
  }
  if (h > 0) ans += (h + a[n - 1] - 1) / a[n - 1];
  cout << ans << endl;
  return 0;
}
