#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n, h, a = 0;
  cin >> n >> h;
  vector<ll> b(n + 1);
  for (ll i = 0, t; i < n; ++i) {
    cin >> t >> b[i];
    a = max(a, t);
  }
  sort(b.begin(), b.end(), greater<ll>());
  ll ans = h;
  for (ll i = 0; 0 <= h && i <= n; ++i) {
    if (h == 0)
      ans = min(ans, i);
    else
      ans = min(ans, i + h / a + (h % a ? 1 : 0));
    h -= b[i];
  }
  cout << ans << endl;
  return 0;
}
