#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
int main() {
  int n, h;
  cin >> n >> h;
  vector<ll> a(n), b(n);
  for (int i = 0; i < (int)(n); i++) cin >> a[i] >> b[i];
  sort((a).rbegin(), (a).rend());
  sort((b).rbegin(), (b).rend());
  int ans = 0;
  for (int i = 0; i < (int)(n); i++) {
    if (b[i] < a[0] || h <= 0) break;
    h -= b[i];
    ans++;
  }
  ans += (h / a[0]);
  cout << ans << endl;
}
