#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  pair<int, int> pi[200005];
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    pi[i * 2] = make_pair(b, 1);
    pi[i * 2 + 1] = make_pair(a, 0);
  }
  sort(pi, pi + 2 * n);
  int ans = 0;
  for (int i = 0; i < 2 * n; i++) {
    if (h < 0) break;
    if (pi[n * 2 - 1 - i].second == 0) {
      ans += h / pi[n * 2 - 1 - i].first;
      if (h % pi[n * 2 - 1 - i].first > 0) ans++;
      break;
    }
    h -= pi[n * 2 - 1 - i].first;
    ans++;
  }
  cout << ans << endl;
}
