#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  int N;
  ll H;
  cin >> N >> H;
  vector<ll> a(N), b(N);
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  ll ans = LLONG_MAX;
  vector<ll> tb(N + 1, 0);
  for (int i = 1; i <= N; i++) tb[i] = tb[i - 1] + b[i - 1];
  for (int i = 0; i <= N; i++) {
    ans = min(ans, (H - tb[i] + a[0] - 1) / a[0] + i);
  }
  cout << ans << endl;
}
