#include <bits/stdc++.h>
using ll = long long;
using ld = long double;
using namespace std;
const int INF = 1e9 + 100;
const ll INF64 = 7e18l;
const int mod = 1000000007;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  ll n, h;
  cin >> n >> h;
  vector<ll> a(n), b(n);
  ll max_a = 0;
  for (ll i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    max_a = max(max_a, a[i]);
  }
  sort((b).begin(), (b).end());
  ll ans = 0;
  for (int i = 0; i < n; i++) {
    if (h > 0) {
      if (b[i] >= max_a) {
        ans++;
        h = h - b[i];
      }
    } else {
      cout << ans << endl;
      return 0;
    }
  }
  if (h <= 0) {
    cout << ans << endl;
    return 0;
  }
  if (h % max_a == 0)
    ans += h / max_a;
  else
    ans += h / max_a + 1;
  cout << ans << endl;
  return 0;
}
