#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  int a, b[100001] = {};
  int ma = 0;
  for (int i = 0; i < n; ++i) {
    cin >> a >> b[i];
    ma = max(ma, a);
  }
  sort(b, b + n, greater<int>());
  int ans = 0;
  for (int i = 0; i <= n; ++i) {
    h -= b[i];
    ans++;
    if (b[i] <= ma) {
      ans += ceil(h / ma);
      h = 0;
    }
    if (h <= 0) break;
  }
  cout << ans << endl;
  return 0;
}
