#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int64_t n, h;
  cin >> n >> h;
  vector<int64_t> a(n), b(n);
  int64_t amax = 0;
  for (int i = 0; i < n; ++i) {
    cin >> a[i] >> b[i];
    amax = max(amax, a[i]);
  }
  sort(b.rbegin(), b.rend());
  int64_t bmin;
  for (bmin = 0; bmin < n; ++bmin) {
    if (b[bmin] <= amax) {
      break;
    }
  }
  int64_t ans = 0;
  int64_t hp = h;
  for (int i = 0; 0 < hp && i < bmin; ++i) {
    ++ans;
    hp -= b[i];
  }
  ans += (hp + amax - 1) / amax;
  cout << ans << "\n";
}
