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